jdx/mise · error

user service '{name}' must set a non-empty `command`

Error message

user service '{name}' must set a non-empty `command`

What it means

A user service with a custom `command` must supply non-empty text. The command is trimmed and, if empty (e.g. `""` or whitespace), parsing fails because an empty command would produce a unit that does nothing.

Source

Thrown at src/system/user_services.rs:131

                    Some(exe) => Some(
                        std::iter::once(quote_program(&exe.to_string_lossy()))
                            .chain(definition.args.iter().map(|arg| arg.to_string()))
                            .collect::<Vec<_>>()
                            .join(" "),
                    ),
                    None => {
                        unresolved = Some(
                            "no durable mise executable; install mise on this host first"
                                .to_string(),
                        );
                        None
                    }
                }
            }
            (None, Some(command)) => {
                let command = command.trim();
                if command.is_empty() {
                    bail!("user service '{name}' must set a non-empty `command`");
                }
                Some(command.to_string())
            }
        };
        Ok(Self {
            name,
            description,
            command,
            unresolved,
            builtin: config.builtin,
            restart: restart.unwrap_or_default(),
            nice,
            environment: config.environment,
            working_directory: config.working_directory,
            requires_tools: config.requires_tools,
            state: config.state,
            enabled: config.enabled,
            origin,

View on GitHub (pinned to afd2eddd3a)

Solutions

1. Set `command` to the actual command line to run
2. Remove the entry if no command is needed
3. Interpolate a non-empty value if using templated config

Example fix

// before
[[bootstrap.linux.user_services]]
name = "my-agent"
command = ""

// after
[[bootstrap.linux.user_services]]
name = "my-agent"
command = "my-agent --daemon"

fn validate_command(s: &UserServiceConfig) -> Result<(), String> {
    if let Some(c) = &s.command {
        if c.trim().is_empty() {
            return Err(format!("user service '{}': command must be non-empty", s.name));
        }
    }
    Ok(())
}

When it happens

Trigger: `command = ""` or `command = " "` on a user service entry, hitting the `(None, Some(command))` arm's empty check at src/system/user_services.rs:131.

Common situations: Leaving a placeholder empty string in config; templating that expands to an empty value; clearing a command while keeping the entry.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• user service '{name}' cannot be masked; use `state = "absent
• user service '{name}': `on_change` only applies to system se
• user service '{name}' sets both `builtin` and `command`; cho
• user service '{name}' must set `command` or `builtin`
• user service '{name}' names unknown builtin '{builtin_name}'

AI-assisted analysis of jdx/mise@afd2eddd3a (2026-09-09). Data as JSON: /api/errors/1186100ffc6a96ad. Report an issue: GitHub.