mislav/hub · error

alias starting with ! can't be split

Error message

alias starting with ! can't be split

What it means

Aliases whose command string begins with `!` denote shell (external) commands, which splitAliasCmd intentionally refuses to split into gh arguments. Invoking such an alias returns this error so the shell form can be handled elsewhere rather than mis-tokenized.

Source

Thrown at commands/runner.go:163

	}
}

func isBuiltInHubCommand(command string) bool {
	for hubCommand := range CmdRunner.All() {
		if hubCommand == command {
			return true
		}
	}
	return false
}

func splitAliasCmd(cmd string) ([]string, error) {
	if cmd == "" {
		return nil, fmt.Errorf("alias can't be empty")
	}

	if strings.HasPrefix(cmd, "!") {
		return nil, fmt.Errorf("alias starting with ! can't be split")
	}

	words, err := shellquote.Split(cmd)
	if err != nil {
		return nil, err
	}

	return words, nil
}

View on GitHub (pinned to 5c547ed804)

Solutions

1. Remove the leading `!` and set a plain gh command alias: `gh alias set <name> 'pr list'`.
2. If a shell command is needed, define a real shell alias/function or script instead of a gh alias.
3. Delete the alias if it's obsolete: `gh alias delete <name>`.

Example fix

// before
gh alias set deploy "!./deploy.sh"
// after: run the script directly in your shell, or
gh alias set deploy "workflow run deploy"

if strings.HasPrefix(aliasBody, "!") {
    return fmt.Errorf("alias %q uses shell syntax (!); gh aliases accept only gh commands", aliasName)
}

When it happens

Trigger: Invoking a gh alias whose stored value starts with `!` (e.g. `gh alias set say '!echo hi'`) — expandAlias passes "!echo hi" to splitAliasCmd, which rejects it via the strings.HasPrefix(cmd, "!") check.

Common situations: User set up a shell-escape alias expecting gh to run it; config copied from another tool (like git) where `!` aliases are supported; version differences where shell aliases were deprecated in gh.

Related errors

• alias can't be empty
• Error: couldn't detect shell type. Please specify your shell
• hub alias: unsupported shell supported shells: %s
• Unsupported flag -b when checking out pull request
• Unsupported flag --orphan when checking out pull request

AI-assisted analysis of mislav/hub@5c547ed804 (2026-09-01). Data as JSON: /api/errors/d618703a884cc2b2. Report an issue: GitHub.