chenhg5/cc-connect · error

chmod: %w

Error message

chmod: %w

What it means

Wraps a failed os.Chmod(0755) on the downloaded replacement binary in replaceExecutable. It fires when the temp file cannot be marked executable — unusual filesystems, or the temp file vanished (cleaned by another process).

Source

Thrown at cmd/cc-connect/update.go:430

	if err != nil {
		return "", err
	}

	size, err := io.Copy(tmp, resp.Body)
	if err != nil {
		tmp.Close()
		os.Remove(tmp.Name())
		return "", fmt.Errorf("write: %w", err)
	}
	tmp.Close()

	fmt.Printf("Downloaded %.1f MB\n", float64(size)/1024/1024)
	return tmp.Name(), nil
}

func replaceExecutable(target, src string) error {
	if err := os.Chmod(src, 0o755); err != nil {
		return fmt.Errorf("chmod: %w", err)
	}

	// On Windows, rename over a running exe is not possible directly.
	// Move old binary aside, then move new one in.
	backup := target + ".old"
	os.Remove(backup)

	if err := os.Rename(target, backup); err != nil {
		return fmt.Errorf("backup old binary: %w", err)
	}

	if err := copyFile(src, target); err != nil {
		// Attempt to restore
		if restoreErr := os.Rename(backup, target); restoreErr != nil {
			slog.Warn("update: failed to restore old binary after copy error", "error", restoreErr)
		}
		return fmt.Errorf("install new binary: %w", err)
	}

View on GitHub (pinned to 4000b2338a)

Solutions

1. Check that TMPDIR is not on a noexec/odd filesystem
2. Point TMPDIR to a normal local directory
3. Retry the update

When it happens

Trigger: Thrown at cmd/cc-connect/update.go:430 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of chenhg5/cc-connect@4000b2338a (2026-09-06). Data as JSON: /api/errors/4ca20985f7a6f832. Report an issue: GitHub.