ahmetb/kubectx · error

failed to write temp kubeconfig: %w

Error message

failed to write temp kubeconfig: %w

What it means

Writing the extracted kubeconfig bytes to the already-created temp file failed (tmpFile.Write). The file was created successfully, so this is a mid-write I/O failure: disk full or the file descriptor became invalid.

Source

Thrown at cmd/kubectx/shell_session.go:89

		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
	cmd.Stderr = os.Stderr
	cmd.Env = append(os.Environ(),
		append([]string{
			"KUBECONFIG=" + tmpPath,
			env.EnvIsolatedShell + "=1",
		}, s.extraEnv...)...,
	)

View on GitHub (pinned to 12ad6fb22e)

Solutions

1. Free space in the temp directory /tmp or TMPDIR
2. Check dmesg for I/O or filesystem errors on the temp mount
3. Retry after freeing space; the temp file is cleaned up automatically

When it happens

Trigger: Thrown at cmd/kubectx/shell_session.go:89 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/a74ce36b9cee7caa. Report an issue: GitHub.