ahmetb/kubectx · error

failed to create temp kubeconfig file: %w

Error message

failed to create temp kubeconfig file: %w

What it means

Returned by run when os.CreateTemp fails to create a temporary file for the per-context kubeconfig extracted earlier in the session setup. This happens when the OS cannot provide a temp file — typically a full/writable-missing TMPDIR, permission problems, or resource exhaustion — meaning the isolated shell session cannot be started, so the whole shell-session operation aborts with this wrapped error.

Source

Thrown at cmd/kubectx/shell_session.go:82

		return fmt.Errorf("failed to extract kubeconfig for context: %w", err)
	}

	// Optionally transform the kubeconfig (e.g. rewrite for readonly proxy).
	var cleanup func()
	if s.transformKubeconfig != nil {
		data, cleanup, err = s.transformKubeconfig(data)
		if err != nil {
			return err
		}
		if cleanup != nil {
			defer cleanup()
		}
	}

	// Write kubeconfig to temp file.
	tmpFile, err := os.CreateTemp("", "kubectx-shell-*.yaml")
	if err != nil {
		return fmt.Errorf("failed to create temp kubeconfig file: %w", err)
	}
	tmpPath := tmpFile.Name()
	defer os.Remove(tmpPath)

	if _, err := tmpFile.Write(data); err != nil {
		tmpFile.Close()
		return fmt.Errorf("failed to write temp kubeconfig: %w", err)
	}
	tmpFile.Close()

	// Print entry message.
	s.printEntry(stderr, s.target)

	// Detect and start shell.
	shellBin := detectShell()
	cmd := exec.Command(shellBin)
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout

View on GitHub (pinned to 12ad6fb22e)

Solutions

1. Check TMPDIR is writable and has free space (df -h /tmp)
2. Set TMPDIR to a writable directory and retry
3. Check for inode exhaustion if disk space looks fine

When it happens

Trigger: Thrown at cmd/kubectx/shell_session.go:82 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ahmetb/kubectx@12ad6fb22e (2026-09-02). Data as JSON: /api/errors/0c08090837ab4f8f. Report an issue: GitHub.