[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14737606999168,
    "event_type": "GoCreate",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14737607005120,
    "event_type": "GoStart",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14737607013376,
    "event_type": "GoCreate",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14737607022400,
    "event_type": "GoStart",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 3,
  "timestamp_ns": 14737607022400,
  "event_type": "GoStart",
  "goroutine_id": 8,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "7": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "8": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoCreate", "goroutine_id": 37}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14737606999168,
    "event_type": "GoCreate",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14737607005120,
    "event_type": "GoStart",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14737607013376,
    "event_type": "GoCreate",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14737607022400,
    "event_type": "GoStart",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 3,
  "timestamp_ns": 14737607022400,
  "event_type": "GoStart",
  "goroutine_id": 8,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "7": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "8": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoCreate", "goroutine_id": 21}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14737606999168,
    "event_type": "GoCreate",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14737607005120,
    "event_type": "GoStart",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14737607013376,
    "event_type": "GoCreate",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14737607022400,
    "event_type": "GoStart",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 3,
  "timestamp_ns": 14737607022400,
  "event_type": "GoStart",
  "goroutine_id": 8,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "7": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "8": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoStart", "goroutine_id": 36}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14737606999168,
    "event_type": "GoCreate",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14737607005120,
    "event_type": "GoStart",
    "goroutine_id": 7,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14737607013376,
    "event_type": "GoCreate",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14737607022400,
    "event_type": "GoStart",
    "goroutine_id": 8,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "7": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "8": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 3,
  "timestamp_ns": 14737607022400,
  "event_type": "GoStart",
  "goroutine_id": 8,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "7": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "8": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoStart", "goroutine_id": 7}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14740663984768,
    "event_type": "GoCreate",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14740663987712,
    "event_type": "GoStart",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14740663988480,
    "event_type": "GoCreate",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14740663994880,
    "event_type": "GoCreate",
    "goroutine_id": 21,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14740663999360,
    "event_type": "GoStart",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14740664002624,
    "event_type": "GoCreate",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14740664007360,
    "event_type": "GoStart",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 6,
  "timestamp_ns": 14740664007360,
  "event_type": "GoStart",
  "goroutine_id": 22,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "19": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "20": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "21": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
    },
    "22": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoBlock", "goroutine_id": 19}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14740663984768,
    "event_type": "GoCreate",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14740663987712,
    "event_type": "GoStart",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14740663988480,
    "event_type": "GoCreate",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14740663994880,
    "event_type": "GoCreate",
    "goroutine_id": 21,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14740663999360,
    "event_type": "GoStart",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14740664002624,
    "event_type": "GoCreate",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14740664007360,
    "event_type": "GoStart",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 6,
  "timestamp_ns": 14740664007360,
  "event_type": "GoStart",
  "goroutine_id": 22,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "19": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "20": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "21": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
    },
    "22": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoStart", "goroutine_id": 38}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14740663984768,
    "event_type": "GoCreate",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14740663987712,
    "event_type": "GoStart",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14740663988480,
    "event_type": "GoCreate",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14740663994880,
    "event_type": "GoCreate",
    "goroutine_id": 21,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14740663999360,
    "event_type": "GoStart",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14740664002624,
    "event_type": "GoCreate",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14740664007360,
    "event_type": "GoStart",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 6,
  "timestamp_ns": 14740664007360,
  "event_type": "GoStart",
  "goroutine_id": 22,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "19": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "20": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "21": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
    },
    "22": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoCreate", "goroutine_id": 10}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14740663984768,
    "event_type": "GoCreate",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14740663987712,
    "event_type": "GoStart",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14740663988480,
    "event_type": "GoCreate",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14740663994880,
    "event_type": "GoCreate",
    "goroutine_id": 21,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14740663999360,
    "event_type": "GoStart",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14740664002624,
    "event_type": "GoCreate",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14740664007360,
    "event_type": "GoStart",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 6,
  "timestamp_ns": 14740664007360,
  "event_type": "GoStart",
  "goroutine_id": 22,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "19": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "20": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "21": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
    },
    "22": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoStart", "goroutine_id": 7}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14740663984768,
    "event_type": "GoCreate",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14740663987712,
    "event_type": "GoStart",
    "goroutine_id": 19,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14740663988480,
    "event_type": "GoCreate",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14740663994880,
    "event_type": "GoCreate",
    "goroutine_id": 21,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14740663999360,
    "event_type": "GoStart",
    "goroutine_id": 20,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14740664002624,
    "event_type": "GoCreate",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14740664007360,
    "event_type": "GoStart",
    "goroutine_id": 22,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "19": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "20": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "21": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "22": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 6,
  "timestamp_ns": 14740664007360,
  "event_type": "GoStart",
  "goroutine_id": 22,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "19": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "20": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "21": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
    },
    "22": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoStart", "goroutine_id": 36}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14738618353152,
    "event_type": "GoCreate",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14738618356480,
    "event_type": "GoCreate",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14738618362560,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14738618363328,
    "event_type": "GoCreate",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14738618367936,
    "event_type": "GoCreate",
    "goroutine_id": 38,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14738618374272,
    "event_type": "GoStart",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14738618383872,
    "event_type": "GoSched",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 7,
    "timestamp_ns": 14738618389696,
    "event_type": "GoStart",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 8,
    "timestamp_ns": 14738618393152,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 9,
    "timestamp_ns": 14738618395712,
    "event_type": "GoBlock",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "blocked",
        "blocked_on": "chan receive",
        "locals_hint": "runtime.chanrecv1"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 9,
  "timestamp_ns": 14738618395712,
  "event_type": "GoBlock",
  "goroutine_id": 35,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "35": {
      "status": "blocked",
      "blocked_on": "chan receive",
      "locals_hint": "runtime.chanrecv1"
    },
    "36": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "37": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "38": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "main.(*Rows).initContextClose"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoBlock", "goroutine_id": 36}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14738618353152,
    "event_type": "GoCreate",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14738618356480,
    "event_type": "GoCreate",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14738618362560,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14738618363328,
    "event_type": "GoCreate",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14738618367936,
    "event_type": "GoCreate",
    "goroutine_id": 38,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14738618374272,
    "event_type": "GoStart",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14738618383872,
    "event_type": "GoSched",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 7,
    "timestamp_ns": 14738618389696,
    "event_type": "GoStart",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 8,
    "timestamp_ns": 14738618393152,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 9,
    "timestamp_ns": 14738618395712,
    "event_type": "GoBlock",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "blocked",
        "blocked_on": "chan receive",
        "locals_hint": "runtime.chanrecv1"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 9,
  "timestamp_ns": 14738618395712,
  "event_type": "GoBlock",
  "goroutine_id": 35,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "35": {
      "status": "blocked",
      "blocked_on": "chan receive",
      "locals_hint": "runtime.chanrecv1"
    },
    "36": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "37": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "38": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "main.(*Rows).initContextClose"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoBlock", "goroutine_id": 8}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14738618353152,
    "event_type": "GoCreate",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14738618356480,
    "event_type": "GoCreate",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14738618362560,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14738618363328,
    "event_type": "GoCreate",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14738618367936,
    "event_type": "GoCreate",
    "goroutine_id": 38,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14738618374272,
    "event_type": "GoStart",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14738618383872,
    "event_type": "GoSched",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 7,
    "timestamp_ns": 14738618389696,
    "event_type": "GoStart",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 8,
    "timestamp_ns": 14738618393152,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 9,
    "timestamp_ns": 14738618395712,
    "event_type": "GoBlock",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "blocked",
        "blocked_on": "chan receive",
        "locals_hint": "runtime.chanrecv1"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 9,
  "timestamp_ns": 14738618395712,
  "event_type": "GoBlock",
  "goroutine_id": 35,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "35": {
      "status": "blocked",
      "blocked_on": "chan receive",
      "locals_hint": "runtime.chanrecv1"
    },
    "36": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "37": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "38": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "main.(*Rows).initContextClose"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoBlock", "goroutine_id": 7}


[System] You are a code execution simulator.

[User]
You are reasoning about concurrent Go program execution.

Here is a Go program:
<program>
// WEAVE_META
// outcome: leak
// concurrency_pattern: channel
// goroutine_count: 3
// expected_nondeterminism: medium
// description: Human-written GoBench bug kernel cockroach_13755 (leak)

/*
 * Project: cockroach
 * Issue or PR  : https://github.com/cockroachdb/cockroach/pull/13755
 * Buggy version: 7acb881bbb8f23e87b69fce9568d9a3316b5259c
 * fix commit-id: ef906076adc1d0e3721944829cfedfed51810088
 * Flaky: 100/100
 * Description: The buggy code does not close the db query result (rows),
 * so that one goroutine running (*Rows).awaitDone is blocked forever.
 * The blocking goroutine is waiting for cancel signal from context.
 */

package main

import (
	"os"
	"runtime/trace"
	"context"
	)

type Rows struct {
	cancel context.CancelFunc
}

func (rs *Rows) initContextClose(ctx context.Context) {
	ctx, rs.cancel = context.WithCancel(ctx)
	go rs.awaitDone(ctx)
}

func (rs *Rows) awaitDone(ctx context.Context) {
	<-ctx.Done()
	rs.close(ctx.Err())
}

func (rs *Rows) close(err error) {
	// rs.cancel()
}

/// G1 						G2
/// initContextClose()
/// 						awaitDone()
/// 						<-tx.ctx.Done()
/// return
/// ---------------G2 leak-----------------
func main() {
	if tf := os.Getenv("WEAVE_TRACE_FILE"); tf != "" {
		f, err := os.Create(tf)
		if err == nil {
			if err := trace.Start(f); err == nil {
				defer func() { trace.Stop(); f.Close() }()
			}
		}
	}

	rs := &Rows{}
	rs.initContextClose(context.Background())
	// FIX: rs.close()
}

</program>

Here is a partial execution trace showing goroutine scheduler events so far:
<trace>
[
  {
    "event_id": 0,
    "timestamp_ns": 14738618353152,
    "event_type": "GoCreate",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 1,
    "timestamp_ns": 14738618356480,
    "event_type": "GoCreate",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.traceStartReadCPU"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 2,
    "timestamp_ns": 14738618362560,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 3,
    "timestamp_ns": 14738618363328,
    "event_type": "GoCreate",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 4,
    "timestamp_ns": 14738618367936,
    "event_type": "GoCreate",
    "goroutine_id": 38,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime/trace.(*traceMultiplexer).startLocked"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 5,
    "timestamp_ns": 14738618374272,
    "event_type": "GoStart",
    "goroutine_id": 37,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 6,
    "timestamp_ns": 14738618383872,
    "event_type": "GoSched",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.(*traceAdvancerState).start"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 7,
    "timestamp_ns": 14738618389696,
    "event_type": "GoStart",
    "goroutine_id": 36,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "runtime.wakeNetPoller"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 8,
    "timestamp_ns": 14738618393152,
    "event_type": "GoStart",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  },
  {
    "event_id": 9,
    "timestamp_ns": 14738618395712,
    "event_type": "GoBlock",
    "goroutine_id": 35,
    "goroutines": {
      "1": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "35": {
        "status": "blocked",
        "blocked_on": "chan receive",
        "locals_hint": "runtime.chanrecv1"
      },
      "36": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "37": {
        "status": "running",
        "blocked_on": null,
        "locals_hint": "unknown"
      },
      "38": {
        "status": "runnable",
        "blocked_on": null,
        "locals_hint": "main.(*Rows).initContextClose"
      }
    },
    "channels": {},
    "mutexes": {}
  }
]
</trace>

The current goroutine states are:
<current_state>
{
  "event_id": 9,
  "timestamp_ns": 14738618395712,
  "event_type": "GoBlock",
  "goroutine_id": 35,
  "goroutines": {
    "1": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "35": {
      "status": "blocked",
      "blocked_on": "chan receive",
      "locals_hint": "runtime.chanrecv1"
    },
    "36": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "37": {
      "status": "running",
      "blocked_on": null,
      "locals_hint": "unknown"
    },
    "38": {
      "status": "runnable",
      "blocked_on": null,
      "locals_hint": "main.(*Rows).initContextClose"
    }
  },
  "channels": {},
  "mutexes": {}
}
</current_state>

Predict the next scheduler event. What happens next?
Respond in JSON only — no markdown fences, no text outside the JSON object:
{"event_type":"GoStart|GoBlock|GoUnblock|GoCreate|GoEnd|GoSched","goroutine_id":<integer>,"reasoning":"<brief explanation>","confidence":"high|medium|low"}

[Assistant] {"event_type": "GoSched", "goroutine_id": 20}