[Blender Harness] Windows path escape bug in render script

[cr88128]

;Bug Description
When executing render execute on Windows, the generated Python script contains Windows paths that are not properly escaped, causing a SyntaxError in Blender.

Environment

• Windows (confirmed on Windows 10/11)
• Blender 5.1.2
• Python path in script: C:\Users\cr881\Desktop\_render_script.py
• Error: SyntaxError: (unicode error) 'unicodeescape' codec can't decode bytes in position 19-20: truncated \UXXXXXXXX escape

Steps to Reproduce

cli-anything-blender scene new --name TestScene -o test_scene.json
cli-anything-blender --project test_scene.json object add cube -n "MyCube" -l "0,0,1"
cli-anything-blender light add sun -n "SunLight"
cli-anything-blender --project test_scene.json render execute "C:\Users\cr881\Desktop\blender_test.png" --overwrite

Then run the generated script directly with Blender:

blender --background --python C:\Users\cr881\Desktop\_render_script.py

Expected vs Actual
Expected: Blender renders the scene successfully to the specified PNG file.

Actual: Blender crashes with a syntax error because the Python script contains raw Windows paths (e.g., C:\Users\...) that Python interprets as Unicode escape sequences.

Root Cause
In the generated _render_script.py file, line 80 contains:

print('Render complete: C:\Users\cr881\Desktop\blender_test.png')

The backslashes in the Windows path need to be escaped as \\ or use a raw string / forward slashes.

Suggested Fix
Use forward slashes or proper path escaping in the generated render script:

• Option 1: Use pathlib.Path or os.path.abspath to normalize paths
• Option 2: Replace \ with \\ in string literals
• Option 3: Use raw strings (r"C:\path") for file paths
• Option 4: Use forward slashes (C:/Users/...) which Python and Blender both accept on Windows

Additional Context

• GIMP CLI works perfectly on Windows with no such issues
• This appears to be specific to the Blender harness render script generation
• The harness otherwise functions correctly (scene creation, object/light addition all work)

[omerarslan0]

Confirmed. The generated render script embeds output_path straight into Python string literals in blender/agent-harness/cli_anything/blender/utils/bpy_gen.py:

• :514 print('Render complete: {output_path}') — no prefix, so C:\Users\... hits the \U unicodeescape error. This is the crash you're seeing.
• :494 scene.render.filepath = r'{output_path}' — the actual output line. The r'...' prefix avoids the escape error but is still fragile: a raw string can't end in a backslash, and a path containing ' breaks out of the literal.
• :143 bpy.data.images.load(r'{hdri_path}') — same fragility for HDRI paths.

Don't hand-escape or rely on the raw-string prefix. Embed paths with repr() (or json.dumps()), which produces a correctly-quoted, fully-escaped Python literal for any path — backslashes, quotes, and trailing separators all handled:

f"scene.render.filepath = {output_path!r}",
f"print('Render complete: ' + {output_path!r})",
f"env_tex.image = bpy.data.images.load({hdri_path!r})",

Apply it to all three sites. A regression test that generates a script with a Windows-style path (C:\Users\x\out.png) and compile()s the result would lock this down.