[Windows] Hooks silently broken: python3 Store stub passes command -v but fails to execute

[benslockedin]

Description

On Windows, all ALIVE hooks that depend on Python silently fail. This means:

• project.py never runs (no _kernel/now.json generation after save)
• generate-index.py never runs (no world index regeneration)
• JSON field extraction returns empty strings (squirrel entries populate with engine: unknown, walnut: null)
• No error is surfaced to the user (all failures are swallowed by 2>/dev/null)

The system appears to work (hooks don't crash, squirrel files get created) but is actually running blind.

Root Cause

Windows ships a python3 stub at AppData/Local/Microsoft/WindowsApps/python3.exe that is actually AppInstallerPythonRedirector.exe:

• Passes command -v python3 (the file exists and is executable)
• Fails when actually run: exits with code 49 and prints "Python was not found"

In alive-common.sh, command -v python3 succeeds so ALIVE_JSON_RT is set to "python3". The node fallback (which works perfectly on Windows) never triggers.

Environment

• OS: Windows 11 Home 10.0.26200
• Shell: Git Bash (MINGW64) via Claude Code
• Python: Available via py -3 launcher but NOT via python3
• Node: Working, but never reached as fallback

Impact

Feature	Status on Windows
Squirrel creation	Partial (file created, fields empty)
JSON parsing in hooks	Broken (returns empty strings)
project.py (now.json generation)	Never runs
generate-index.py (world index)	Never runs
Statusline	Degraded
PreToolUse guards	May silently skip checks
Post-save chain	Broken

Fix

Fixed in #29 (commit de8d602). The detection now validates execution, not just existence, and adds a py -3 fallback with a shim:

if command -v python3 &>/dev/null && python3 -c "" &>/dev/null 2>&1; then
  ALIVE_JSON_RT="python3"
elif command -v py &>/dev/null && py -3 -c "" &>/dev/null 2>&1; then
  python3() { py -3 "$@"; }
  export -f python3
  ALIVE_JSON_RT="python3"
elif command -v node &>/dev/null; then
  ALIVE_JSON_RT="node"
fi

Reporter

Stuart Smyth — discovered during Windows onboarding.