multica-ai/multica · error

rename temp to %s: %w

Error message

rename temp to %s: %w

What it means

writeFileAtomic wrote, chmod'd, and closed the temp file but os.Rename over the destination failed. The rename-in-same-directory design rules out EXDEV in normal operation, so this is usually a Windows sharing violation (another process holds the open destination) or a permission problem on replacing the destination entry.

Source

Thrown at server/internal/daemon/execenv/hermes_home.go:933

	tmp, err := os.CreateTemp(dir, ".hermes-tmp-*")
	if err != nil {
		return fmt.Errorf("create temp for %s: %w", dst, err)
	}
	tmpName := tmp.Name()
	defer os.Remove(tmpName) // no-op once renamed
	if _, err := tmp.Write(data); err != nil {
		tmp.Close()
		return fmt.Errorf("write temp for %s: %w", dst, err)
	}
	if err := tmp.Chmod(perm); err != nil {
		tmp.Close()
		return fmt.Errorf("chmod temp for %s: %w", dst, err)
	}
	if err := tmp.Close(); err != nil {
		return fmt.Errorf("close temp for %s: %w", dst, err)
	}
	if err := os.Rename(tmpName, dst); err != nil {
		return fmt.Errorf("rename temp to %s: %w", dst, err)
	}
	return nil
}

View on GitHub (pinned to 2c0912b6ec)

Solutions

1. Stop overlapping processes on the same env (one task per env RootDir; previous child fully exited) and retry.
2. On Windows, exclude the env root from AV/indexing; retry after handles release.
3. Check rename permission on the directory for the daemon UID and any MAC denials in audit logs.
4. Delete the dst file manually if it is stuck; prepare recreates it atomically.

err := writeFileAtomic(dst, data, perm)
if err != nil {
	var le syscall.Errno
	if errors.As(err, &le) && le == syscall.Errno(32) { // EACCES/sharing-violation class on Windows
		time.Sleep(200 * time.Millisecond)
		err = writeFileAtomic(dst, data, perm) // holders often release quickly
	}
}
return err

When it happens

Trigger: On Windows, a reader (Hermes child, AV, indexer) holds dst open at replace time; dst is a directory while the temp is a file; the dir was made read-only or foreign-owned between CreateTemp and Rename;SELinux/AppArmor denying rename.

Common situations: A task's Hermes process still reading config.yaml while the next prepare refreshes it; antivirus scanning freshly written temp files on Windows; containers with restrictive MAC policy on the env volume.

Related errors

• remove legacy task state %s: %w
• clear hermes skills dir: %w
• runtime local skill import timed out
• replace binary: %w
• mirror %s: %w

AI-assisted analysis of multica-ai/multica@2c0912b6ec (2026-08-15). Data as JSON: /api/errors/9e53d5613b88c670. Report an issue: GitHub.