Update app.py

app.py

@@ -1,11 +1,12 @@
 import os
-os.environ["MPLCONFIGDIR"] = "/tmp"
+os.environ["MPLCONFIGDIR"] = "/tmp"  # matplotlib sans ~/.config
+
 import gradio as gr
 from pathlib import Path
 import subprocess, json, tempfile, sys
 
 COMFY_DIR = Path("ComfyUI")
-WORKFLOW_JSON = Path("workflow_api.json")   # we’ll create it later
+WORKFLOW_JSON = Path("workflow_api.json")
 
 def patch_workflow(wf, pic_path, face_path, prompt):
     for node in wf.values():
@@ -31,17 +32,21 @@ def run(picture, face, positive):
     with open(tmp_wf, "w") as f:
         json.dump(wf, f)
 
-    subprocess.run([
-        sys.executable, "ComfyUI/main.py",
+    result = subprocess.run([
+        sys.executable, "main.py",
         "--disable-auto-launch",
         "--input", str(tmpdir),
         "--output", str(tmpdir),
         "--workflow", str(tmp_wf)
-    ], cwd=COMFY_DIR, check=True)
+    ], cwd=COMFY_DIR, capture_output=True, text=True)
+
+    if result.returncode != 0:
+        print("ComfyUI error:", result.stderr)
+        raise RuntimeError("ComfyUI failed to run")
 
     out = list(tmpdir.glob("*.png"))
     if not out:
-        raise RuntimeError("No output image")
+        raise RuntimeError("No output image generated.")
     return out[0]
 
 demo = gr.Interface(
@@ -56,4 +61,5 @@ demo = gr.Interface(
     title="ComfyUI InstantID Face Swap",
     allow_flagging="never"
 )
+
 demo.queue().launch(server_name="0.0.0.0", server_port=7860, share=True)