Windows: graphify rebuild for Java/Spring Boot projects is unstable (python3 launcher, wrong output root, os.replace WinError 5, and silent success on failure) #287

Summary

I found several issues when using Graphify on Windows with a Spring Boot / Java project (with both src/main and src/test) after running graphify codex install.

The current rebuild/update flow is not stable in this setup.

Issues observed

1. python3 in AGENTS.md is unreliable on Windows
   The generated command uses:

   python3 -c "from graphify.watch import _rebuild_code; from pathlib import Path; _rebuild_code(Path('.'))"

   On my machine, python3 points to the WindowsApps stub launcher, exits with code 1, and produces no useful error output.

2. Wrong output/cache root for Java project layout
   In a Spring Boot project with both src/main and src/test, _rebuild_code(Path('.')) may infer the wrong root and generate graphify-out inside a nested package path such as:

   src/main/java/com/nsoc/graphify-out
   

   instead of the repository root:

   <repo>/graphify-out
   

3. Cache replace can fail with WinError 5
   The cache write path uses temp file -> os.replace(). On Windows this can fail with WinError 5, causing rebuild failure.

4. Failure is silent when _rebuild_code() returns False
   The generated command does not convert a False return value into a non-zero exit code, so Codex may think rebuild succeeded even when it failed.

Why this matters

These issues make Graphify/Codex integration unreliable on Windows:

• rebuild may not run
• output may be written to the wrong directory
• rebuild may fail due to Windows file locking behavior
• failure may still look like success

This can leave Codex working against stale or broken graphify-out data.

Suggested fixes

• Use a Windows-safe Python invocation for Codex integration (py -3, python, or a generated wrapper script)
• Keep rebuild output anchored to the repository root
• Make cache writes more robust on Windows (PermissionError retry/fallback)
• Exit non-zero when _rebuild_code() fails

Environment

• OS: Windows
• Project type: Spring Boot / Java
• Layout includes:
  • src/main/java/...
  • src/test/java/...