fix(gwai): avoid worktree output capture race

Author: Ynakatsuka

.github/workflows/check.yml

@@ -20,6 +20,8 @@ jobs:
         run: bash scripts/test-rtk-rewrite-hook.sh
       - name: Test my-pr worktree transfer
         run: bash scripts/test-my-pr-worktree-move.sh
+      - name: Test gwai-cmux worktree capture
+        run: bash scripts/test-gwai-cmux-worktree-capture.sh
       - name: Test mise upgrade wrapper
         run: |
           command -v jq >/dev/null

home/dot_local/bin/executable_gwai-cmux

@@ -128,37 +128,29 @@ Task: ${prompt}"
 create_worktree() {
   local base_dir="$1"
   local branch_name="$2"
-  local creation_output worktree_dir output_file helper_status
-
-  output_file=$(mktemp) || die "failed to create temporary output file"
-  : >"$output_file"
+  local worktree_dir helper_status
 
   set +e
-  (cd "$base_dir" && gw-create-worktree "$branch_name") \
-    > >(tee -a "$output_file" >&2) \
-    2> >(tee -a "$output_file" >&2)
+  (cd "$base_dir" && gw-create-worktree "$branch_name")
   helper_status=$?
   set -e
 
-  creation_output=$(cat "$output_file") || {
-    rm -f "$output_file"
-    die "failed to read worktree creation output"
-  }
-  rm -f "$output_file"
-
   [[ "$helper_status" -eq 0 ]] ||
     die "failed to create worktree for branch: $branch_name"
 
-  worktree_dir=$(printf '%s\n' "$creation_output" |
-    awk -F= '$1 == "WORKTREE_PATH" { print substr($0, index($0, "=") + 1) }' |
-    tail -1)
+  worktree_dir=$(git -C "$base_dir" worktree list --porcelain |
+    awk -v b="$branch_name" '
+      /^worktree/ { wt = substr($0, index($0, " ") + 1) }
+      $1 == "branch" && $2 == "refs/heads/" b && found == "" { found = wt }
+      END { if (found != "") print found }
+    ')
 
   [[ -n "$worktree_dir" ]] ||
-    die "gw-create-worktree did not output WORKTREE_PATH"
+    die "failed to resolve worktree for branch: $branch_name"
   [[ -d "$worktree_dir" ]] ||
     die "worktree path does not exist: $worktree_dir"
 
-  printf '%s\n' "$worktree_dir"
+  created_worktree_dir="$worktree_dir"
 }
 
 create_prompt_file() {
@@ -334,6 +326,7 @@ base_dir=""
 branch_name=""
 prompt_file=""
 workspace_ref=""
+created_worktree_dir=""
 inside_tab=0
 prompt_parts=()
 
@@ -476,6 +469,7 @@ rename_current_cmux_workspace "$branch_name" "$workspace_ref"
 printf '[gwai-cmux] Branch: %s\n' "$branch_name"
 printf '[gwai-cmux] Creating worktree...\n'
 
-worktree_dir=$(create_worktree "$base_dir" "$branch_name")
+create_worktree "$base_dir" "$branch_name"
+worktree_dir="$created_worktree_dir"
 printf '[gwai-cmux] Starting %s in %s\n' "$provider" "$worktree_dir"
 start_agent "$provider" "$worktree_dir" "$prompt"

scripts/test-gwai-cmux-worktree-capture.sh

@@ -0,0 +1,109 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+repo_root=$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd -P)
+gwai_cmux_script="${GWAI_CMUX_SCRIPT:-$repo_root/home/dot_local/bin/executable_gwai-cmux}"
+test_dir=$(mktemp -d "${TMPDIR:-/tmp}/gwai-cmux-worktree-capture-test.XXXXXX")
+test_dir=$(cd "$test_dir" && pwd -P)
+background_pid=""
+
+cleanup() {
+  if [[ -n "$background_pid" ]] && kill -0 "$background_pid" 2>/dev/null; then
+    kill "$background_pid"
+    wait "$background_pid" 2>/dev/null || true
+  fi
+  rm -rf "$test_dir"
+}
+trap cleanup EXIT
+
+fail() {
+  printf 'FAIL: %s\n' "$*" >&2
+  exit 1
+}
+
+bin_dir="$test_dir/bin"
+base_dir="$test_dir/base"
+worktree_dir="$test_dir/worktree"
+run_output="$test_dir/run-output"
+cmux_log="$test_dir/cmux.log"
+zsh_log="$test_dir/zsh.log"
+background_pid_file="$test_dir/background.pid"
+mkdir -p "$bin_dir" "$base_dir"
+git init -q "$base_dir"
+git -C "$base_dir" config user.name 'gwai-cmux test'
+git -C "$base_dir" config user.email 'gwai-cmux@example.invalid'
+printf 'base\n' >"$base_dir/base.txt"
+git -C "$base_dir" add base.txt
+git -C "$base_dir" commit -qm 'test: add base file'
+
+cat >"$bin_dir/cmux" <<'MOCK'
+#!/usr/bin/env bash
+set -euo pipefail
+
+printf '%s\n' "$*" >>"$TEST_CMUX_LOG"
+MOCK
+
+cat >"$bin_dir/gw-create-worktree" <<'MOCK'
+#!/usr/bin/env bash
+set -euo pipefail
+
+sleep 5 &
+printf '%s\n' "$!" >"$TEST_BACKGROUND_PID_FILE"
+printf 'helper progress (stdout)\n'
+printf 'helper progress (stderr)\n' >&2
+git -C "$TEST_BASE_DIR" worktree add -q -b "$1" "$TEST_WORKTREE_DIR"
+printf 'WORKTREE_PATH=%s\n' "$TEST_WORKTREE_DIR"
+MOCK
+
+cat >"$bin_dir/zsh" <<'MOCK'
+#!/usr/bin/env bash
+set -euo pipefail
+
+printf '%s\n' "$*" >"$TEST_ZSH_LOG"
+MOCK
+
+chmod +x "$bin_dir/cmux" "$bin_dir/gw-create-worktree" "$bin_dir/zsh"
+
+started_at=$(date +%s)
+set +e
+PATH="$bin_dir:/usr/bin:/bin" \
+  CMUX_BIN="$bin_dir/cmux" \
+  CMUX_WORKSPACE_ID='' \
+  TEST_BACKGROUND_PID_FILE="$background_pid_file" \
+  TEST_BASE_DIR="$base_dir" \
+  TEST_CMUX_LOG="$cmux_log" \
+  TEST_WORKTREE_DIR="$worktree_dir" \
+  TEST_ZSH_LOG="$zsh_log" \
+  bash "$gwai_cmux_script" \
+  --inside-tab \
+  --provider codex \
+  --base-dir "$base_dir" \
+  --branch-name fix-worktree-capture \
+  'capture race regression' >"$run_output" 2>&1
+run_status=$?
+set -e
+elapsed_seconds=$(($(date +%s) - started_at))
+
+((run_status == 0)) || {
+  printf '%s\n' "$(<"$run_output")" >&2
+  fail "gwai-cmux exited with status $run_status"
+}
+((elapsed_seconds < 4)) ||
+  fail "gwai-cmux waited for the helper's background child (${elapsed_seconds}s)"
+
+[[ -s "$background_pid_file" ]] || fail "helper did not start its background child"
+background_pid=$(<"$background_pid_file")
+kill -0 "$background_pid" 2>/dev/null ||
+  fail "helper background child was not still running"
+
+grep -Fqx -- 'rename-workspace --title fix-worktree-capture' "$cmux_log" ||
+  fail "cmux workspace rename was not requested"
+grep -Fq -- "cd $worktree_dir && cdx capture\\ race\\ regression" "$zsh_log" ||
+  fail "start_agent did not receive the expected worktree path"
+grep -Fq -- 'helper progress (stdout)' "$run_output" ||
+  fail "helper stdout was not visible"
+grep -Fq -- 'helper progress (stderr)' "$run_output" ||
+  fail "helper stderr was not visible"
+
+printf 'test-gwai-cmux-worktree-capture: OK\n'