[Bug?]: Package subpath imports don't work with the ESM loader

[evanw]

Self-service

• I'd be willing to implement a fix

Describe the bug

It appears that when PnP is enabled, Yarn's ESM loader doesn't support subpath imports correctly (i.e. imports that start with # in a package with an imports map in its package.json file). It looks like Yarn thinks it's a package instead, which then fails to be imported because it's not listed in that package's dependencies.

To reproduce

$ yarn init -2
$ yarn set version 3.2.3
$ yarn config set pnpEnableEsmLoader true
$ yarn add aws-jwt-verify@3.1.0
$ echo 'import "aws-jwt-verify"' > in.mjs
$ yarn node in.mjs
.pnp.cjs:8466
  return Object.defineProperties(new Error(message), {
                                 ^

Error: aws-jwt-verify tried to access #node-web-compat, but it isn't declared in its dependencies; this makes the require call ambiguous and unsound.

Required package: #node-web-compat (via "#node-web-compat/package.json")
Required by: aws-jwt-verify@npm:3.1.0 (via .yarn/cache/aws-jwt-verify-npm-3.1.0-1694314cd9-b978817018.zip/node_modules/aws-jwt-verify/dist/esm/jwt-rsa.js)

    at makeError (.pnp.cjs:8466:34)
    at resolveToUnqualified (.pnp.cjs:9385:21)
    at Object.resolveToUnqualified (.pnp.cjs:9529:26)
    at resolve$1 (.pnp.loader.mjs:224:31)
    at ESMLoader.resolve (node:internal/modules/esm/loader:530:30)
    at ESMLoader.getModuleJob (node:internal/modules/esm/loader:251:18)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:79:40)
    at link (node:internal/modules/esm/module_job:78:36)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)

Environment

System:
    OS: Linux 5.4 Ubuntu 20.04.4 LTS (Focal Fossa)
    CPU: (2) x64 DO-Regular
  Binaries:
    Node: 16.14.0 - /tmp/xfs-e3802538/node
    Yarn: 3.2.3 - /tmp/xfs-e3802538/yarn
    npm: 8.7.0 - ~/node/bin/npm

Additional context

Someone filed an issue about this package not working with esbuild's implementation of PnP: evanw/esbuild#2545. But Yarn itself doesn't work with this package either. I'm guessing this is a bug with Yarn.

[merceyz]

I'm guessing this is a bug with Yarn.

We haven't implemented it yet, closing as a duplicate of #3843