jdx/mise · error

brew prune is not supported on windows

Error message

brew prune is not supported on windows

What it means

The brew prune path in mise is compiled only for unix targets. On non-unix builds (Windows), `run_brew` is a stub that unconditionally bails, because Homebrew does not exist on Windows and there is no formula-prune implementation to fall back to.

Solutions

1. Run `mise system prune brew` on macOS or Linux instead of Windows
2. Skip the brew prune step in Windows CI/scripts (guard on OS)
3. If you need Windows package cleanup, use a Windows-native manager (e.g. scoop/winget flows) rather than the brew manager

Example fix

// before (windows runner)
- run: mise system prune brew
// after
- run: mise system prune brew
  if: runner.os != 'Windows'

[[ "$(uname -s)" != MINGW* && "$(uname -s)" != CYGWIN* ]] && mise system prune brew

mise system prune brew 2>/dev/null || echo 'brew prune unsupported on this platform'

When it happens

Trigger: Invoking `mise system prune brew` (run_inner dispatching by manager name) on a Windows build of mise — the `#[cfg(not(unix))]` stub always returns this error regardless of arguments.

Common situations: Windows users attempting Homebrew-style package pruning, e.g. after copying unix documentation or scripts; CI matrix accidentally running the brew prune step on a windows runner.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

• brew-cask prune is not supported on windows
• app target is outside an allowed Applications directory
• artifact target has changed
• binary target is not an owned Caskroom symlink
• brew-cask is not available

AI-assisted analysis of jdx/mise@533346cc37 (2026-09-17). Data as JSON: /api/errors/c33fa2abb504009d. Report an issue: GitHub.

Appendix: source

Thrown at src/cli/system/prune.rs:224

            .iter()
            .map(|candidate| format!("{}@{}", candidate.token, candidate.version))
            .collect::<Vec<_>>();
        if !self.yes && !Settings::get().yes && console::user_attended_stderr() {
            let msg = format!("brew-cask: prune {}?", remove.join(", "));
            if !prompt::confirm(msg)?.is_yes() {
                info!("brew-cask: skipped");
                return Ok(());
            }
        }
        let removed = brew::apply_cask_prune_plan(&plan, false)?;
        info!("brew-cask: pruned {removed} casks");
        Ok(())
    }

    #[cfg(not(unix))]
    async fn run_brew(self) -> Result<()> {
        let _ = self.manager;
        bail!("brew prune is not supported on windows")
    }

    #[cfg(not(unix))]
    async fn run_brew_cask(self) -> Result<()> {
        let _ = self.manager;
        bail!("brew-cask prune is not supported on windows")
    }
}

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