pulumi/pulumi · error

unable to allocate tmp file: %w

Error message

unable to allocate tmp file: %w

What it means

When starting the Delve debugger, the language host creates a temporary log file with os.CreateTemp("", "pulumi-go-dlv-") for debugger logs; if temp file creation fails the host aborts debugger startup with this error. It reflects a filesystem/environment problem, not a problem with your program.

Source

Thrown at sdk/go/pulumi-language-go/main.go:915

			c.Port = p
			break
		}
	}
	return nil
}

func (c *debugger) Cleanup() {
	contract.IgnoreError(os.Remove(c.LogDest))
}

func debugCommand(ctx context.Context, bin string, binArgs ...string) (*exec.Cmd, *debugger, error) {
	godlv, err := executable.FindExecutable("dlv")
	if err != nil {
		return nil, nil, fmt.Errorf("unable to find 'dlv' executable: %w", err)
	}
	logFile, err := os.CreateTemp("", "pulumi-go-dlv-")
	if err != nil {
		return nil, nil, fmt.Errorf("unable to allocate tmp file: %w", err)
	}
	contract.IgnoreClose(logFile)
	args := []string{"--headless=true", "--api-version=2"}
	args = append(args, "--log", "--log-dest", logFile.Name())
	port, err := netutil.FindNextAvailablePort(preferredDebugPort)
	if err == nil {
		args = append(args, "--listen=127.0.0.1:"+strconv.Itoa(port))
	}
	args = append(args, "exec", bin)
	if len(binArgs) > 0 {
		args = append(args, "")
		args = append(args, binArgs...)
	}
	dlvCmd := exec.CommandContext(ctx, godlv, args...)
	return dlvCmd, &debugger{Host: "127.0.0.1", LogDest: logFile.Name()}, nil
}

func startDebugging(ctx context.Context, engineClient pulumirpc.EngineClient, dbg *debugger, name string) error {

View on GitHub (pinned to 793f7b2e16)

Solutions

1. Check TMPDIR: `echo $TMPDIR` and confirm the directory exists and is writable; unset or fix it if broken.
2. Free disk space on the volume backing /tmp.
3. Verify you can create files: `touch /tmp/pulumi-test && rm /tmp/pulumi-test`.
4. If debugging was unintended, remove the `--debug` flag so no debugger temp file is created.

Example fix

// before
$ export TMPDIR=/nonexistent
$ pulumi up --debug
error: unable to allocate tmp file: open /nonexistent/pulumi-go-dlv-...: no such file or directory
// after
$ unset TMPDIR   # or point it at a writable dir
$ pulumi up --debug

if dir := os.TempDir(); dir == "" {
    return errors.New("TMPDIR unset")
} else if f, err := os.CreateTemp(dir, "pulumi-test-"); err != nil {
    return fmt.Errorf("temp dir not writable: %w", err)
} else {
    f.Close(); os.Remove(f.Name())
}

err := pulumiUp(ctx, "--debug")
if err != nil && strings.Contains(err.Error(), "unable to allocate tmp file") {
    // fix TMPDIR / disk space and retry
}

When it happens

Trigger: debugCommand runs during `pulumi up --debug` for a Go project and os.CreateTemp fails (typically because TMPDIR is unwritable, full, or misconfigured).

Common situations: TMPDIR pointing to a nonexistent or read-only directory; disk full; hardened containers/seccomp denying file creation in /tmp; extremely restrictive umask or security policies.

Related errors

• create global project dir: %w
• filesystem extra root %q is not a directory
• resolving shell cwd: %w
• resolving shell extra root %q: %w
• shell extra root %q: %w

AI-assisted analysis of pulumi/pulumi@793f7b2e16 (2026-08-31). Data as JSON: /api/errors/deafd3947119b07b. Report an issue: GitHub.