Add a `use-pnpm-version` option to .npmrc to specify a project-specific version and use it automatically about pnpm

[SuperchupuDev]

i believe you can use corepack and the packageManager package.json field for that

[zkochan]

Yes, just use corepack if you need this.

[deej-io]

Thank you for the suggestions of using corepack. This is an improvement but it still has some pain points.

1. By default the shims are installed to /usr/bin, unless configured otherwise, which requires root and clobbers any package-manager installed version.
2. If a different installation directory is chosen, we have to make sure that is on the PATH, and this still shadows the package-manager installed version.
3. It's another tool and setup step that makes onboarding more complicated than it needs to be.

Additionally, I'm not convinced by the "there is an existing tool" argument as the same could be made for the built-in Node version management, as nvm and volt already exist.

I think that there is real value in the idea that you can install an up-to-date version of pnpm and that's all you need if the project has been configured to specify the required versions.

[zkochan]

Our goal should be to make pnpm reliable enough, so that you don't care which version you run. You don't select a specific version of Git for your project, right?

So, as there is corepack at the moment, I don't think we should work on this. Maybe we'll do it some day but I don't think it is a priority. I don't see any problem with corepack except that you won't be able to globally manage node.js with pnpm if you use it. Corepack is easy to use because it is shipped with node.js, you just need to run corepack enable. Hence, I am not convinced that it complicates onboarding. We can print more details in the error message, when the package manager field is present and pnpm's version doesn't match.