[Feature] Support env variables in yarnrc

• I’d be willing to implement this feature
• This feature can already be implemented through a plugin

Describe the user story

yarn v1 supports env variables in yarnrc/npmrc:

//registry.npmjs.org/:_authToken=${COMPANY_NPM_TOKEN}

but v2 doesn’t support it in .yarnrc.yml

Describe the solution you’d like

It would be nice to support env variables like in other tools/libraries (for example docker compose)

[arcanis]

Fixed in https://github.com/yarnpkg/berry/pull/1341 💫

[DaneTheory]

You can inject runtime environment variables, including variables already defined within the active shell, by rerouting the yarnPath defined in .yarnrc.yml to a custom path containing a .js file which instantiates a valid Yarn v2 release in the form of a child_process. At that point, declaring custom process.env values is straight-forward. Though it does feel a bit hacky. Check out @yarkPkg Berry’s repo and you can see they do exactly that. However, I imagine best practices would be to utilize the pnpapi lifecycle as according to the docs.