ipfs/kubo · error

creating temp file: %w

Error message

creating temp file: %w

What it means

`writeBinaryToTempFile` creates a uniquely named executable temp file (via `os.CreateTemp` with pattern `ipfs-<version>-*`) to hold a downloaded binary before it is atomically moved into place. This error wraps the `os.CreateTemp` failure, meaning no temp file could be created at all.

Source

Thrown at core/commands/update.go:723

	if err != nil {
		return err
	}

	if _, err := af.Write(data); err != nil {
		_ = af.Abort()
		return err
	}

	return af.Close()
}

// writeBinaryToTempFile writes data to a uniquely named executable file
// in the system temp directory and returns its path.
func writeBinaryToTempFile(data []byte, ver string) (path string, err error) {
	pattern := migrations.ExeName(fmt.Sprintf("ipfs-%s-*", ver))
	f, err := os.CreateTemp("", pattern)
	if err != nil {
		return "", fmt.Errorf("creating temp file: %w", err)
	}
	defer func() {
		if cerr := f.Close(); cerr != nil && err == nil {
			err = fmt.Errorf("closing temp file: %w", cerr)
		}
		if err != nil {
			os.Remove(f.Name())
		}
	}()

	if _, err = f.Write(data); err != nil {
		return "", fmt.Errorf("writing temp file: %w", err)
	}
	if err = f.Sync(); err != nil {
		return "", fmt.Errorf("syncing temp file: %w", err)
	}
	if err = f.Chmod(0o755); err != nil {
		return "", fmt.Errorf("chmod temp file: %w", err)

View on GitHub (pinned to 329838acdf)

Solutions

1. Check the temp dir: `df -h /tmp` and `ls -ld /tmp` (expect drwxrwxrwt); free space or fix permissions.
2. Set TMPDIR to a writable directory before running the update: `TMPDIR="$HOME/tmp" ipfs update ...` (create it first).
3. Fix directory ACLs/ownership if running as an unprivileged user in a container; or run with a writable overlayfs layer.
4. Investigate MAC denials (auditd/SELinux) if permissions look correct but creation still fails.

Example fix

# before
ipfs update install v0.30.0   # creating temp file: open /tmp/...: no space left on device

# after
clean_tmp_space_or_choose_other_dir
export TMPDIR="$HOME/tmp"
mkdir -p "$TMPDIR"
ipfs update install v0.30.0

tmp := os.TempDir()
probe := filepath.Join(tmp, ".update-probe")
if err := os.WriteFile(probe, []byte("x"), 0o600); err != nil {
	// temp dir unusable: repoint TMPDIR or fix permissions before updating
	os.Remove(probe)
}
if free, _ := freeSpace(tmp); free < 200<<20 {
	// less than ~200MB free: clean up first
}

func tempDirWritable() bool {
	f, err := os.CreateTemp(os.TempDir(), ".kubo-probe-*")
	if err != nil {
		return false
	}
	f.Close()
	os.Remove(f.Name())
	return true
}

path, err := writeBinaryToTempFile(data, ver)
if err != nil {
	if strings.Contains(err.Error(), "creating temp file") {
		// hint: TMPDIR broken — fall back to an explicit writable dir
		os.Setenv("TMPDIR", "/var/tmp")
		return retryUpdate()
	}
	return err
}

When it happens

Trigger: `ipfs update install`/download path when the system temp dir (TMPDIR or /tmp) is unwritable or full, TMPDIR points to a nonexistent directory, or permission bits on /tmp block the current user.

Common situations: Disk-full /tmp; containers running as non-root with a read-only tmpfs; TMPDIR exported incorrectly in scripts; SELinux/AppArmor denying writes to the temp dir.

Related errors

• reading stash directory: %w
• chmod temp file: %w
• serveHTTPApi: SetAPIAddr() failed: %w
• %s is not writeable by the current user
• cannot write to %s, incorrect permissions

AI-assisted analysis of ipfs/kubo@329838acdf (2026-09-03). Data as JSON: /api/errors/76a3127776ccbf25. Report an issue: GitHub.