[BUG] Bash hooks (PreToolUse/PostToolUse) silently not invoked on Windows with settings.local.json-only config

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

PreToolUse and PostToolUse Bash hooks configured in .claude/settings.local.json are never invoked on Windows. No Bash tool call triggers the configured
scripts, despite a full Claude Code restart from the project root. The hook subprocess appears to never be spawned: a trace echo added as the first
executable line of the hook script never writes to disk after Bash tool calls.

What Should Happen?

PreToolUse Bash hook should run before every Bash tool call; PostToolUse Bash hook should run after. Both should have their subprocess spawned and their
stdin receive the JSON tool input, regardless of whether there is a sibling settings.json file in the project.

Error Messages/Logs

Evidence collected (what I already ruled out):

  1. Script correctness — invoked directly with a JSON stub it works as intended:
     $ echo '{"tool_input":{"command":"env | head"}}' | "C:\PROGRA~1\Git\usr\bin\bash.exe" /c/myproject/.claude/hooks/my-precheck.sh
     BLOCKED: <expected message>
     (exit 1)

  2. Trace probe — the hook script has this as its first executable line:
     echo "$(date -u) pid=$$" >> /c/myproject/.claude/hooks/precheck.trace
     After many Bash tool calls post-restart, the trace file does not exist.
     The hook process is never spawned.

  3. Post-hook log frozen — the PostToolUse hook appends to a log on every call.
     mtime stays at the pre-restart timestamp; zero new entries despite dozens of
     Bash tool calls since restart.

  4. CC does track hooks in principle — ~/.claude.json contains
     pre_tool_hook_duration_ms_count counters with non-zero histories from other
     sessions, so the feature is wired at the client level, just not firing for
     this config.

  5. Tooling verified — jq 1.8.1 in PATH, bash path C:\Program Files\Git\usr\bin\bash.exe
     resolves, short form C:\PROGRA~1\Git\usr\bin\bash.exe also resolves, forward-slash
     script paths (/c/...) work when called manually.

  No hook-related errors surface anywhere visible to me (transcript, CC UI, any log file I could find).

  ---
  Steps to Reproduce (campo reproduction):
  1. On Windows with Git Bash installed, create a project with **only** `.claude/settings.local.json`
     (no sibling `settings.json`, no user-global `~/.claude/settings.json`). Content:

     {
       "hooks": {
         "PreToolUse": [
           {
             "matcher": "Bash",
             "hooks": [
               {
                 "type": "command",
                 "command": "C:\\PROGRA~1\\Git\\usr\\bin\\bash.exe /c/tmp/trace.sh",
                 "timeout": 5
               }
             ]
           }
         ]
       }
     }

  2. Create C:\tmp\trace.sh:

     #!/usr/bin/env bash
     echo "fired $(date -u +%s) pid=$$" >> /c/tmp/cc-hook-trace.log
     exit 0

  3. Fully close Claude Code, reopen from the project root.

  4. Issue any Bash tool call in the session (e.g. ask Claude to run `ls`).

  5. Observe: /c/tmp/cc-hook-trace.log is never created.

  Expected: the file exists with one `fired ...` line per Bash tool call.
  Actual: the file is never created. The hook subprocess is never spawned.

Steps to Reproduce

1. On Windows with Git Bash installed, create a project with only .claude/settings.local.json

(no sibling settings.json, no user-global ~/.claude/settings.json). Content:

{
"hooks": {
"PreToolUse": [
{
"matcher": "Bash",
"hooks": [
{
"type": "command",
"command": "C:\\PROGRA~1\\Git\\usr\\bin\\bash.exe /c/tmp/trace.sh",
"timeout": 5
}
]
}
]
}
}

1. Create C:\tmp\trace.sh:

#!/usr/bin/env bash
echo "fired $(date -u +%s) pid=$$" >> /c/tmp/cc-hook-trace.log
exit 0

1. Fully close Claude Code, reopen from the project root.

1. Issue any Bash tool call in the session (e.g. ask Claude to run ls).

1. Observe: /c/tmp/cc-hook-trace.log is never created.

Expected: the file exists with one fired ... line per Bash tool call.
Actual: the file is never created. The hook subprocess is never spawned.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.114

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

• Is settings.local.json alone sufficient on Windows for hook registration, or is a sibling settings.json required even if the docs don't state it?
• Is there a CC debug flag, env var, or log file that exposes whether the hook subprocess was attempted (and its stdout/stderr/exit) — analogous to the

pre_tool_hook_duration_ms telemetry in ~/.claude.json, but with per-invocation records?

• Any known Windows-specific gotcha with the "command" field format (quoting, spaces in Program Files, short-name path PROGRA~1)?

Happy to provide more detail on request.