Recognize index.lock contention in worktrees and submodules

The retry check matched the literal ".git/index.lock", which only ever
appears for the main worktree. A linked worktree's lock is at
.git/worktrees/<name>/index.lock and a submodule's is under its own git
dir, so contention there was never retried. Match the bare "index.lock"
fragment instead, which covers all of them.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

pkg/commands/git_cmd_obj_runner.go

@@ -24,12 +24,17 @@ type gitCmdObjRunner struct {
 // lock-related condition that may succeed on retry. The lock message can reach
 // us either in the command's captured output or, for streamed commands whose
 // output we don't capture, only in the returned error, so we check both.
+//
+// We match the bare "index.lock" fragment rather than a fuller path or message
+// so we catch the lock wherever git puts it: the main .git dir, a linked
+// worktree's git dir (.git/worktrees/<name>/index.lock), or a submodule's git
+// dir.
 func isRetryableError(output string, err error) bool {
 	text := output
 	if err != nil {
 		text += "\n" + err.Error()
 	}
-	return strings.Contains(text, ".git/index.lock") ||
+	return strings.Contains(text, "index.lock") ||
 		strings.Contains(text, "cannot lock ref")
 }
 

pkg/commands/git_cmd_obj_runner_test.go

@@ -105,3 +105,18 @@ func TestRunWithOutputRetriesWhenLockErrorIsOnlyInError(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, 2, inner.calls)
 }
+
+func TestRunWithOutputRetriesLockErrorInLinkedWorktree(t *testing.T) {
+	// In a linked worktree the lock lives at .git/worktrees/<name>/index.lock
+	// rather than .git/index.lock, so only matching the bare "index.lock"
+	// fragment lets the retry fire there too.
+	inner := &scriptedRunner{results: []runnerResult{
+		{output: "", err: errors.New("fatal: Unable to create '/repo/.git/worktrees/feature/index.lock': File exists.")},
+		{output: "", err: nil},
+	}}
+
+	_, err := newTestRunner(inner).RunWithOutput(dummyCmdObj())
+
+	assert.NoError(t, err)
+	assert.Equal(t, 2, inner.calls)
+}