brew-cask:{}: Homebrew owns this cask; remove it with Homebr

Error message

brew-cask:{}: Homebrew owns this cask; remove it with Homebrew before installing it with mise

What it means

Before installing a cask, mise checks whether the Caskroom token directory contains Homebrew's `.metadata` marker (homebrew_metadata_present). If it exists, the cask was installed by Homebrew itself; mise refuses to take over an install it does not own, because overwriting would corrupt brew's receipts and break `brew upgrade`/`uninstall`.

Source

Thrown at src/system/packages/brew/cask.rs:384

    }

    async fn install_one_with_ancestors(
        &self,
        req: &PackageRequest,
        opts: &InstallOpts,
        pr: Option<&dyn SingleReport>,
        ancestors: &BTreeSet<String>,
    ) -> Result<String> {
        let cask = fetch_cask(req).await?;
        if ancestors.contains(&cask.token) {
            bail!("brew-cask:{}: dependency cycle detected", cask.token);
        }
        let mut ancestors = ancestors.clone();
        ancestors.insert(cask.token.clone());
        let artifacts = cask_artifacts(&cask)?;
        validate_platform_support(&cask, &artifacts)?;
        if homebrew_metadata_present(&cask.token) {
            bail!(
                "brew-cask:{}: Homebrew owns this cask; remove it with Homebrew before installing it with mise",
                cask.token
            );
        }
        if installed_cask_version(&cask, &artifacts)?.as_deref() == Some(cask.version.as_str()) {
            info!("brew-cask:{}: already installed", cask.token);
            return Ok(cask.version);
        }
        for conflict in &cask.conflicts_with.cask {
            if !installed_versions(conflict).is_empty() {
                bail!(
                    "brew-cask:{}: conflicts with installed cask {}",
                    cask.token,
                    conflict
                );
            }
        }
        if !cask.depends_on.formula.is_empty() {

View on GitHub (pinned to 9dcfcaa0dc)

Solutions

Uninstall the brew copy first: `brew uninstall --cask <token>`, then re-run the mise command
Or keep managing that cask with brew and remove it from mise's bootstrap/tools config

Example fix

# before
$ mise install brew-cask:google-chrome
error: brew-cask:google-chrome: Homebrew owns this cask; remove it with Homebrew before installing it with mise

# after
$ brew uninstall --cask google-chrome
$ mise install brew-cask:google-chrome

Defensive patterns

Strategy: validation

Validate before calling

// Rust callers using mise internals can pre-check:
fn homebrew_owns(token: &str) -> bool {
    std::path::Path::new(&caskroom(token)).join(".metadata").symlink_metadata().is_ok()
}
// Shell users: ls "$(brew --prefix)/Caskroom/<token>/.metadata" 2>/dev/null && echo brew-owned

Try / catch

Catch the 'Homebrew owns this cask' bail, print `brew uninstall --cask <token>` as remediation, and continue with the remaining packages in the batch.

Prevention

Choose one manager per cask: brew or mise, never both
Before adopting mise bootstrap on a brew-managed machine, uninstall casks you plan to hand to mise
Check for .metadata in the Caskroom token dir when scripting installs

When it happens

Trigger: Running mise install/bootstrap for a cask (e.g. brew-cask:visual-studio-code) that was previously installed with `brew install --cask <token>`, so <Caskroom>/<token>/.metadata exists.

Common situations: Migrating a machine from brew to mise-managed bootstrap; shared machines where another user installed via brew; CI images that pre-install casks with brew and then run mise bootstrap.

Related errors

AI-assisted analysis of jdx/mise@9dcfcaa0dc (2026-08-17). Data as JSON: /api/errors/629f8219c9cbdc90. Report an issue: GitHub.