How to correctly setup homebrew?

Question

I own a Mac M1 with Monterey 12.3.1. I often experience problems uninstalling brew packages. Here an example:

I installed pnpm with homebrew. Then, I tried to uninstall it:

brew uninstall pnpm

If I brew uninstall pnpm, the following message appears:

Error: No such keg: /opt/homebrew/Cellar/pnpm

Still, pnpm is installed:

$> which pnpm                                           
/opt/homebrew/bin/pnpm

So, it seems that homebrew is looking up at Cellar while the package is at /opt/homebrew/bin. I don't get the concept of Cellar. Is it a homebrew configuration problem?

How to fix homebrew to uninstall correctly?

Answer 1

corepack enable && corepack prepare pnpm@latest --activate

As per Corepack docs & pnpm docs.

This won't uninstall Homebrew's pnpm, but it will effectively replace it with Corepack's version.

I had the same issue, but only when using node v18 (via nvm). (I had already run corepack enable in node v16)

With node v16:

% which pnpm
~/.nvm/versions/node/v16.17.0/bin/pnpm

With node v18:

% which pnpm
/opt/homebrew/bin/pnpm

/opt/homebrew/bin/pnpm links to /opt/homebrew/lib/node_modules/pnpm/bin/pnpm.cjs.

Still not sure why it's there, I thought maybe from a brew install node, but brew uninstall node + brew autoremove didn't get rid of it. At any rate, I'm happy just to be back to using Corepack's pnpm.

PS: brew leaves will "list installed formulae that are not dependencies of another installed formula", it only really makes sense to brew uninstall those formulae, as others are just dependencies.