{name} is not an active, installed tool or one of their exec

Error message

{name} is not an active, installed tool or one of their executables

What it means

find_tool looks up a tool by short name, tool name, or id among the currently active/installed toolset versions. If no installed tool matches `name`, it bails. This is mise's guard for commands that operate on an already-installed, active tool (e.g. deriving completion scripts), not for arbitrary uninstalled names.

Source

Thrown at src/packslip.rs:1041

}

/// The active, installed tool called `name`, or the one providing an
/// executable called `name`.
async fn find_tool(
    config: &Arc<Config>,
    ts: &Toolset,
    name: &str,
) -> Result<(Arc<dyn Backend>, ToolVersion)> {
    if let Some(found) = ts.which(config, name).await {
        return Ok(found);
    }
    let by_name = ts
        .list_current_installed_versions(config)
        .into_iter()
        .find(|(b, _)| b.ba().short == name || b.tool_name() == name || b.id() == name);
    match by_name {
        Some(found) => Ok(found),
        None => bail!("{name} is not an active, installed tool or one of their executables"),
    }
}

/// Run one of the tool's own executables and return what it printed.
async fn run_tool(
    config: &Arc<Config>,
    backend: &Arc<dyn Backend>,
    tv: &ToolVersion,
    argv: &[String],
    env: &BTreeMap<String, String>,
) -> Result<String> {
    let Some((program, args)) = argv.split_first() else {
        bail!("an exec entry with no command");
    };
    let Some(path) = backend.which(config, tv, program).await? else {
        bail!("{} has no executable called {program}", tv.style());
    };
    run_resource_command(

View on GitHub (pinned to afd2eddd3a)

Solutions

Run `mise ls` to confirm the tool is installed and active in the current project.
Install the missing tool (`mise use <tool>` or `mise install <tool>`).
Use the exact tool name/id as shown by `mise ls` (short name like `node`, full tool name, or backend id like `npm:typescript`).
cd into (or add config for) the project where the tool is active before running the command.

Example fix

// before: querying an uninstalled tool
mise resource completions ripgrep

// after: install first, use the active tool's name
mise use ripgrep
mise resource completions ripgrep

Defensive patterns

Strategy: validation

Validate before calling

let active: Vec<String> = ts.list_current_installed_versions(config)
    .into_iter()
    .map(|(b, _)| b.ba().short)
    .collect();
if !active.contains(&name) {
    eprintln!("{name} is not installed/active. Active: {active:?}");
}

Try / catch

match find_tool(config, &ts, &name) {
    Ok(tv) => run_tool(config, tv).await?,
    Err(e) if e.to_string().contains("not an active, installed tool") => {
        eprintln!("Install it first: mise use {name}");
    }
    Err(e) => return Err(e),
}

Prevention

Run `mise ls` to confirm a tool is installed and active before referencing it by name.
Use exact names/ids as reported by mise (short name, tool name, or backend id).
cd into the project whose config activates the tool, or add it to the current config.

When it happens

Trigger: Calling completion_script with a name that is not in ts.list_current_installed_versions(config) — the tool isn't installed, isn't active in the current config, or the name doesn't match short name, tool_name, or id.

Common situations: Typo in the tool name; the tool is pinned in a config file but never installed; the tool is active only in another directory's mise.toml; querying by an alias or executable name that doesn't equal the backend short name, tool name, or id.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

AI-assisted analysis of jdx/mise@afd2eddd3a (2026-09-09). Data as JSON: /api/errors/8e676fd800515d29. Report an issue: GitHub.