What causes "unable to run command: %w" in charmbracelet/glow?

Confirm the exact editor command works standalone with a file argument

unable to run command: %w

Error message

unable to run command: %w

What it means

After editor.Cmd successfully builds the command, glow wires os.Stdin/Stdout/Stderr to it and calls c.Run(). This error wraps any failure from that execution: the process could not be spawned, or it exited with a non-zero status. The config file path was already validated (ensureConfigFile ran first), so this is purely about the editor process.

Source

Thrown at config_cmd.go:48

	Hidden:  false,
	Short:   "Edit the glow config file",
	Long:    paragraph(fmt.Sprintf("\n%s the glow config file. We’ll use EDITOR to determine which editor to use. If the config file doesn't exist, it will be created.", keyword("Edit"))),
	Example: paragraph("glow config\nglow config --config path/to/config.yml"),
	Args:    cobra.NoArgs,
	RunE: func(*cobra.Command, []string) error {
		if err := ensureConfigFile(); err != nil {
			return err
		}

		c, err := editor.Cmd("Glow", configFile)
		if err != nil {
			return fmt.Errorf("unable to set config file: %w", err)
		}
		c.Stdin = os.Stdin
		c.Stdout = os.Stdout
		c.Stderr = os.Stderr
		if err := c.Run(); err != nil {
			return fmt.Errorf("unable to run command: %w", err)
		}

		fmt.Println("Wrote config file to:", configFile)
		return nil
	},
}

func ensureConfigFile() error {
	if configFile == "" {
		configFile = viper.GetViper().ConfigFileUsed()
		if err := os.MkdirAll(filepath.Dir(configFile), 0o755); err != nil { //nolint:gosec
			return fmt.Errorf("could not write configuration file: %w", err)
		}
	}

	if ext := path.Ext(configFile); ext != ".yaml" && ext != ".yml" {
		return fmt.Errorf("'%s' is not a supported configuration type: use '%s' or '%s'", ext, ".yaml", ".yml")
	}

View on GitHub (pinned to e3970c813d)

Solutions

Confirm the exact editor command works standalone with a file argument
Use a terminal editor (vim, nano) or add a wait flag: EDITOR="code --wait"
If the editor aborted, fix the underlying cause it printed to stderr and rerun glow config

Example fix

# before
$ EDITOR=code glow config   # exits/renders nothing useful

# after
$ EDITOR="code --wait" glow config
# or
$ EDITOR=vim glow config

Defensive patterns

Strategy: try-catch

Validate before calling

// smoke-test the exact invocation glow will use
c := exec.Command(editorBin, "/tmp/probe.yml")
c.Stdin, c.Stdout, c.Stderr = os.Stdin, os.Stdout, os.Stderr
if err := c.Run(); err != nil {
	log.Fatalf("editor smoke test failed: %v", err)
}

Try / catch

if err := c.Run(); err != nil {
	var exitErr *exec.ExitError
	if errors.As(err, &exitErr) {
		// editor ran but exited non-zero (e.g. vim :cq) — ask the user, keep the file
		return fmt.Errorf("editor exited with status %d; rerun 'glow config' when ready", exitErr.ExitCode())
	}
	// spawn failure (missing binary, permissions, no TTY)
	return fmt.Errorf("unable to run command: %w", err)
}

Prevention

Use a blocking terminal editor (vim/nano) or add a wait flag for GUIs: EDITOR='code --wait'
Run glow config from a real TTY so the editor can take over stdin/stdout
Distinguish ExitError (user aborted) from spawn errors — only the latter indicates a broken EDITOR value

When it happens

Trigger: EDITOR points to a binary that disappeared between lookup and exec (or lookup returned it despite PATH issues); the editor exits non-zero — e.g. quitting vim with :cq; GUI editors like VS Code launched as EDITOR=code without --wait exit immediately or misbehave without a TTY; exec permission denied on the editor binary.

Common situations: EDITOR="code" or EDITOR="subl" without a wait flag; scripts running glow config where stdout is not a terminal; editors that abort when the file is a symlink into a read-only path.

Related errors

AI-assisted analysis of charmbracelet/glow@e3970c813d (2026-08-15). Data as JSON: /api/errors/d694f59955d66b47. Report an issue: GitHub.