[Bug] Claude Code passes invalid `--no-stat` flag to `git show` command

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Still happening.

This is still happening today, in 2.1.15

Still active as of 2.1.19

Just happened to me today...

Version: 2.1.22
Model: opus (claude-opus-4-5-20251101)

<img width="375" height="297" alt="Image" src="https://github.com/user-attachments/assets/31450bfa-98be-4654-b3c7-8bf6875f378c" />

Happening on 2.1.25 as well (not sure about newer versions, I downgraded because of all the performance issues in 2.1.29).

FWIW including instructions in CLAUDE.md doesn't seem to help:

> cat ~/.claude/CLAUDE.md | rg no-stat
* Git commands don't support the `--no-stat` flag, never use it.

Very annoying, should be a simple fix.

⏺ Bash(git show e5f9ca9 --no-stat)
  ⎿  Error: Exit code 128
     fatal: unrecognized argument: --no-stat

This continues to be an annoyance and waste of time. If this is a difficult fix, then explain why or just take care of it already.

As a workaround, you can use a PreToolUse hook to strip that flag from the command. Something like this:

#!/usr/bin/env bash
#
# Claude hook: remove --no-stat from 'git show' calls.
#
# PreToolUse hook that intercepts Bash tool calls and strips --no-stat
# from git show commands, so the diff stat is always shown.
#
# Install like this:
# {
#   "hooks": {
#     "PreToolUse": [
#       {
#         "matcher": "Bash",
#         "hooks": [
#           {
#             "type": "command",
#             "command": "bash /path/to/this/file.sh"
#           }
#         ]
#       }
#     ]
#   }
# }


set -euo pipefail

input=$(cat)

tool_name=$(jq -r '.tool_name // ""' <<< "$input")

# Only handle Bash tool calls
if [[ "$tool_name" != "Bash" ]]; then
  echo '{}'
  exit 0
fi

command=$(jq -r '.tool_input.command // ""' <<< "$input")

# Only handle commands that contain 'git show'
trimmed="${command#"${command%%[![:space:]]*}"}"
if [[ "$trimmed" != git[[:space:]]*show* ]] && [[ "$trimmed" != "git show"* ]]; then
  echo '{}'
  exit 0
fi

# Only act if --no-stat is present
if [[ "$command" != *"--no-stat"* ]]; then
  echo '{}'
  exit 0
fi

# Remove --no-stat (with surrounding whitespace collapsed)
new_command=$(sed -E 's/ --no-stat//' <<< "$command")

jq -n --arg cmd "$new_command" '{
  hookSpecificOutput: {
    hookEventName: "PreToolUse",
    updatedInput: {
      command: $cmd
    }
  }
}'

@drmercer-lucid Did you vibe-code this? 😉

Absolutely 😄 I just wish Claude made it a little easier to vibe code hooks (it's surprisingly tedious to install and test them)

Hook workaround: strip --no-stat automatically
Until this is fixed upstream, you can use a PreToolUse hook to silently rewrite git show ... --no-stat into a valid command.
git-show-flag-sanitizer.sh:

INPUT=$(cat)
COMMAND=$(echo "$INPUT" | jq -r '.tool_input.command // empty' 2>/dev/null)
[ -z "$COMMAND" ] && exit 0
case "$COMMAND" in
  *git\ show*--no-stat*) ;;
  *) exit 0 ;;
esac
NEW_COMMAND=$(echo "$COMMAND" | sed 's/ --no-stat//' | sed 's/  */ /g')
jq -n --arg cmd "$NEW_COMMAND" '{
  hookSpecificOutput: {
    hookEventName: "PreToolUse",
    permissionDecision: "allow",
    updatedInput: { command: $cmd }
  }
}'

Install in .claude/settings.json:

{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "bash /path/to/git-show-flag-sanitizer.sh"
          }
        ]
      }
    ]
  }
}

This intercepts every Bash tool call, checks if it's a git show with --no-stat, strips the invalid flag, and returns the corrected command via updatedInput. Other commands pass through untouched.
The hook is also available as part of cc-safe-setup (tested with 10 test cases).

This still is happening now with 2,1,92 macos

Claude Code does this all the time, it exclusively does this. I've never seen it run a git show without trying git show --no-stat first and watching it fail.

I still see this with v2.1.170.