jdx/mise · error

.\n\n \n\nIf pipx is already installed, verify it with…

Error message

{reason}.\n\n{instructions}\n\nIf pipx is already installed, verify it with `mise which pipx` and `pipx --version`.

What it means

Thrown by the pipx backend's `install_version_` when the `pipx` executable is required to install a Python-tool request but was not found on the system. mise shells out to an external pipx for these installs; without it there is no way to install the package, so mise fails with instructions on how to verify or install pipx.

Solutions

  1. Install pipx and ensure it is on PATH: `pipx --version` to verify; `mise which pipx` to see what mise resolves.
  2. Install pipx through mise itself: `mise use pipx@latest` (or `mise use -g pipx@latest`), then retry the tool install.
  3. If using a custom executable, set the pipx `executable` option/`MISE_PIPX_EXECUTABLE`-style opt to the correct binary path.
  4. In CI, add a step that provisions Python and pipx before running `mise install`.

Example fix

// before (mise.toml)
[tools]
"pipx:black" = "24.4.2"   // fails: no pipx on PATH

// after
[tools]
pipx = "latest"
"pipx:black" = "24.4.2"
Defensive patterns

Strategy: validation

Validate before calling

# run before installing pipx-backed tools
command -v pipx >/dev/null 2>&1 && pipx --version || { echo 'pipx missing'; mise use -g pipx@latest; }

Try / catch

try { await $`mise install` } catch (e) { if (String(e).includes('pipx is required')) { await $`mise use -g pipx@latest`; await $`mise install`; } else throw e; }

Prevention

When it happens

Trigger: Running `mise install`/`mise use pipx:<package>` (e.g. `pipx:ipython`) when `pipx` is absent from PATH, the `pipx_executable` option points to a nonexistent binary, or pipx exists only in an environment not active in the current shell.

Common situations: Fresh machine without pipx installed; pipx installed via `pip install --user` but `~/.local/bin` missing from PATH; using mise in CI where Python/pipx aren't provisioned; a configured custom executable path that moved after a Python upgrade.

Understand the failure class

Background: "not installed", "pip install", "required for": how missing-dependency errors surface across open-source libraries — this error's family across 34 libraries.

Related errors

AI-assisted analysis of jdx/mise@afd2eddd3a (2026-09-09). Data as JSON: /api/errors/ea48aa3541bcd7c6. Report an issue: GitHub.

Appendix: source

Thrown at src/backend/pipx.rs:378

            // below, so it cannot pass on evidence the spawn will then reject. On Windows a
            // `pipx.ps1` or a shebang-only `pipx.pyz` satisfies the plain lookup but cannot
            // be launched, and it used to reach `pipx install` and die with
            // "program not found" instead of these instructions.
            if !pipx_available {
                let pipx_configured = match self.dependency_toolset(&ctx.config).await {
                    Ok(ts) => ts.versions.keys().any(|ba| ba.short == "pipx"),
                    Err(_) => false,
                };
                let reason = if pipx_configured {
                    "pipx is configured but its executable was not found or is not runnable"
                        .to_string()
                } else {
                    format!(
                        "pipx is required to install {} but was not found",
                        self.ba()
                    )
                };
                bail!(
                    "{reason}.\n\n{instructions}\n\nIf pipx is already installed, verify it with `mise which pipx` and `pipx --version`."
                );
            }
        }

        let request = self.tool_name().parse::<PipxRequest>()?;

        if let Some(uv_program) = uv_program {
            let package_request = request.uvx_request(&tv.version, &options);
            self.warn_if_uv_may_not_support_exclude_newer(ctx).await;
            ctx.pr
                .set_message(format!("uv tool install {package_request}"));
            let mut cmd = Self::uvx_cmd(
                &uv_program,
                &ctx.config,
                &["tool", "install", &package_request],
                self,
                &tv,

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