node corepack is broken (yarn, pnpm, ...)

[OmarTawfik]

The preferred way to install tools like yarn and pnpm is through NodeJS corepack command:

• https://yarnpkg.com/getting-started/install

The preferred way to manage Yarn is through Corepack, a new binary shipped with all Node.js releases starting from 16.10. It acts as an intermediary between you and Yarn, and lets you use different package manager versions across multiple projects without having to check-in the Yarn binary anymore.

For projects using hermit, this can be done via:

hermit install node
corepack enable

Which adds new symlinks to the ./bin directory, like yarn, yarnpkg, pnpm, and pnpx. And now I can just invoke them using yarn install as usual, which is great for local development!

However, these symlinks are added relative to my local Hermit folder (MacOS laptop):

ls -la ./bin/yarn
./bin/yarn -> ../../../Library/Caches/hermit/pkg/node-19.2.0/lib/node_modules/corepack/dist/yarn.js

Which means it is broken if I try to use it in CI (ubuntu), or check it into the repository so that other developers use it, since that path is only valid on my machine.

1. Is there an alternative (Hermit-blessed) way of installing tools managed by corepack?
2. If not, can these symlinks be corrected somehow to point to a portable path, that can work across different machines, and in CI?

[alecthomas]

Anything not directly managed by Hermit shouldn't be checked in. This is conceptually similar to using pip, or even npm, for example.

Usually though, we set an environment variable to tell package managers to install into .hermit/<tool> and the package adds that to the path, so if we can figure out how to tell corepack how to do that that would be ideal. You can see an example of that in the Node package itself.

[alecthomas]

Looking at the list of envars, it doesn't seem like there is one to set the install prefix, but it can be done via:

mkdir -p $NPM_CONFIG_PREFIX/bin
corepack enable --install-directory $NPM_CONFIG_PREFIX/bin

We can probably do this in an on install hook.

[alecthomas]

The linked PR is a proof of concept but we should not merge this, as corepack is very explicitly marked experimental:

Due to its experimental status, Corepack currently needs to be explicitly enabled to have any effect.

[alecthomas]

I'm going to close this, as generally Hermit is not in the business of doing anything other than installing the base toolchain. Anything beyond that, such as npm, pip, etc. needs to be managed by the user.

[OmarTawfik]

@alecthomas Many thanks for giving me a pointer. Will try that suggestion locally and see if I can come up with a fix.
We can revisit that issue if/once corepack is stabilized.