marin-community/swe-rebench-v2-CodeWorldModeling

SWE-rebench V2 — CodeWorldModeling Traces

This is a derived dataset. Every record is produced from an instance of nebius/SWE-rebench-V2. It is governed by the SWE-rebench V2 license — see License below — including the requirement to respect each source repository's own license.

Line-by-line Python execution traces for the test suites of SWE-rebench V2 instances, captured by running each instance's tests under a tracer inside Nebius ConTree sandboxes.

Each instance comes with a fix patch. The pipeline traces two kinds of tests:

• Fix-verifying tests (affected=True) — tests that fail before the fix patch and pass after it. These are the tests that demonstrate the bug and its fix. Such a row is traced twice: once before the patch (the failing run) and once after (the passing run).
• Regression-suite tests (affected=False) — the rest of the repository's existing test suite ("broad phase"), each traced once at the fixed revision.

Each row is one (instance_id, test_id) trace.

Schema

Trace shards under data/:

column	type	notes
instance_id	string	SWE-rebench-V2 row id
test_id	string	pytest node id
affected	bool	True = fix-verifying test (fails before the patch, passes after); False = regression-suite test traced once at the fixed revision
text	string	plain-text test source + line-by-line execution trace (see below)

Sentinel rows from instances that failed before any trace was captured are excluded.

Reading a trace

The text of a regression-suite row (affected=False) is the test source followed by a single trace:

<test source>

# --- trace ---
<line-by-line execution trace>

A fix-verifying row (affected=True) carries the test source, the trace from before the fix, the fix patch itself, and the trace from after the fix:

<test source>

# --- pre-patch trace ---
<line-by-line execution trace, before the fix>

# --- patch ---
<the fix patch, in `git diff` form>

# --- post-patch trace ---
<line-by-line execution trace, after the fix>

A trace replays execution one source line at a time. Inline # comments record runtime state:

comment	meaning
# === file::function (line N) ===	execution entered this function frame
# ENTER: arg=value, ...	argument values at the call
# branch=if:True / :False	which way a conditional went
name = expr # name=value	value bound by an assignment (right-margin)
# RETURN from function: value	the frame's return value
# EXCEPTION in function: ...	an exception raised in the frame

Example — a regression-suite trace (affected=False)

Source file mathx.py:

def clamp(value, low, high):
    if value < low:
        return low
    if value > high:
        return high
    return value

Test test_clamp_within_range and its trace:

def test_clamp_within_range():
    assert clamp(5, 0, 10) == 5

# --- trace ---
# === tests/test_mathx.py::test_clamp_within_range (line 1) ===
def test_clamp_within_range():
    assert clamp(5, 0, 10) == 5

# === mathx.py::clamp (line 1) ===
def clamp(value, low, high):
    # ENTER: value=5, low=0, high=10
    if value < low:  # branch=if:False
    if value > high:  # branch=if:False
    return value
    # RETURN from clamp: 5

Example — a fix-verifying trace (affected=True)

The buggy clamp returns low instead of high when value is above the range, so test_clamp_above_range fails. The fix patch corrects it. The pre-patch trace shows the failure, the post-patch trace shows it passing:

def test_clamp_above_range():
    assert clamp(99, 0, 10) == 10

# --- pre-patch trace ---
# === tests/test_mathx.py::test_clamp_above_range (line 1) ===
def test_clamp_above_range():
    assert clamp(99, 0, 10) == 10

# === mathx.py::clamp (line 1) ===
def clamp(value, low, high):
    # ENTER: value=99, low=0, high=10
    if value < low:  # branch=if:False
    if value > high:  # branch=if:True
        return low
    # RETURN from clamp: 0
    # EXCEPTION in test_clamp_above_range: AssertionError: assert 0 == 10

# --- patch ---
diff --git a/mathx.py b/mathx.py
--- a/mathx.py
+++ b/mathx.py
@@ -3,5 +3,5 @@ def clamp(value, low, high):
     if value > high:
-        return low
+        return high
     return value

# --- post-patch trace ---
# === tests/test_mathx.py::test_clamp_above_range (line 1) ===
def test_clamp_above_range():
    assert clamp(99, 0, 10) == 10

# === mathx.py::clamp (line 1) ===
def clamp(value, low, high):
    # ENTER: value=99, low=0, high=10
    if value < low:  # branch=if:False
    if value > high:  # branch=if:True
        return high
    # RETURN from clamp: 10

Joining the per-instance license

metadata/licenses.parquet is a companion file mapping instance_id -> license (the source repository's license at the instance commit). It is kept separate so the multi-GB trace shards do not carry a redundant per-row string. Join it on instance_id to attach the license to any trace row.

With datasets:

from datasets import load_dataset

REPO = "marin-community/swe-rebench-v2-CodeWorldModeling"

traces = load_dataset(REPO, split="train")
licenses = load_dataset(REPO, data_files="metadata/licenses.parquet", split="train")

license_by_instance = dict(zip(licenses["instance_id"], licenses["license"]))
traces = traces.map(lambda row: {"license": license_by_instance[row["instance_id"]]})

With pandas:

import pandas as pd

base = "hf://datasets/marin-community/swe-rebench-v2-CodeWorldModeling"
traces = pd.read_parquet(f"{base}/data")
licenses = pd.read_parquet(f"{base}/metadata/licenses.parquet")
traces = traces.merge(licenses, on="instance_id", how="left")

Provenance

• Source dataset: nebius/SWE-rebench-V2
• Generator: experiments/swe_rebench_trace/contree_pipeline.py in marin-community/marin.

License

This dataset is derived from SWE-rebench V2 and inherits its license terms:

The dataset is licensed under the Creative Commons Attribution 4.0 license. However, please respect the license of each specific repository on which a particular instance is based. To facilitate this, the license of each repository at the time of the commit is provided for every instance.

The per-instance source-repository license is provided in the companion file metadata/licenses.parquet (join on instance_id). When using or redistributing these traces, honor the license of the originating repository for each instance.

Citation

Please cite both this dataset and the source dataset it derives from.

This dataset:

@misc{marincommunity2026swerebenchcodeworldmodeling,
      title={SWE-rebench V2 CodeWorldModeling Traces},
      author={Marin Community},
      year={2026},
      howpublished={\url{https://huggingface.co/datasets/marin-community/swe-rebench-v2-CodeWorldModeling}},
}

Source dataset:

@misc{badertdinov2026swerebenchv2languageagnosticswe,
      title={SWE-rebench V2: Language-Agnostic SWE Task Collection at Scale},
      author={Ibragim Badertdinov and Maksim Nekrashevich and Anton Shevtsov and Alexander Golubev},
      year={2026},
      eprint={2602.23866},
      archivePrefix={arXiv},
      primaryClass={cs.SE},
      url={https://arxiv.org/abs/2602.23866},
}