Yarn v2 – post-resolution validation errors

Yarn install seems to succeed, but sits silently after that for about 3.5 minutes. Then it fails with the following:

`The lockfile would have been modified by this install, which is explicitly forbidden.`

I'm now on a brand new application (I was hoping the issue was that my original app was just too stale) and I can't for the life of me figure out why this validation step is failing. From what I can tell, heroku is just running `yarn install` which should produce the same results I have here on my machine.

I've tried clearing the build cache, disabling caching, and killing repo history. I've confirmed that my lockfile is up-to-date, and none of the support articles I've found seem to address the specific error I'm encountering; any relevant ones I have found are focused on the lockfile being out of date, which is a simple fix.

## Buildpacks
- `heroku/nodejs@latest`
- `blockhq/heroku-buildpack-yarn-workspaces@latest` <- new addition I tried out. Result is same.

## Engines
- `Node v12.20.0`
- `Yarn v2.4.1`

## Build Log

```shell
remote: -----> Creating runtime environment
remote:
remote: NPM_CONFIG_LOGLEVEL=info
remote: USE_YARN_CACHE=false
remote: NODE_VERBOSE=true
remote: NODE_ENV=staging
remote: NODE_MODULES_CACHE=false
remote:
remote: -----> Installing binaries
remote: engines.node (package.json): 12.20.0
remote: engines.npm (package.json): unspecified (use default)
remote: engines.yarn (package.json): unspecified (use default)
remote:
remote: Resolving node version 12.20.0...
remote: Downloading and installing node 12.20.0...
remote: Using default npm version: 6.14.8
remote: Resolving yarn version 1.22.x...
remote: Downloading and installing yarn (1.22.10)
remote: Using yarn 2.4.1
remote:
remote: -----> Restoring cache
remote: Caching has been disabled because NODE_MODULES_CACHE=false
remote:
remote: -----> Installing dependencies
remote: Running 'yarn install' with yarn.lock
remote: ➤ YN0000: ┌ Resolution step
remote: ➤ YN0002: │ @endemolshinegroup/cosmiconfig-typescript-loader@npm:3.0.2 [c21ab] doesn't provide typescript (pb7352), requested by ts-node
remote: ➤ YN0002: │ @firebase/auth@npm:0.16.4 [a40cc] doesn't provide @firebase/app-types (pa6d12), requested by @firebase/auth-types
remote: ➤ YN0002: │ @firebase/auth@npm:0.16.4 [a40cc] doesn't provide @firebase/util (p6dbca), requested by @firebase/auth-types
remote: ➤ YN0002: │ @firebase/database@npm:0.8.3 doesn't provide @firebase/app-types (p63919), requested by @firebase/auth-interop-types
remote: ➤ YN0002: │ @firebase/database@npm:0.9.6 doesn't provide @firebase/app-types (p6c6b1), requested by @firebase/auth-interop-types
remote: ➤ YN0002: │ @graphql-tools/graphql-tag-pluck@npm:6.4.0 [4af48] doesn't provide vue (p135cf), requested by @vue/compiler-sfc
remote: ➤ YN0002: │ @graphql-tools/graphql-tag-pluck@npm:6.4.0 [8d221] doesn't provide vue (p92e5e), requested by @vue/compiler-sfc
remote: ➤ YN0060: │ @groupic/api@workspace:packages/api provides graphql (p69d57) with version 14.7.0, which doesn't satisfy what @graphql-codegen/import-types-preset and some of its descendants request
remote: ➤ YN0060: │ @groupic/api@workspace:packages/api provides jest (p20dbd) with version 25.5.4, which doesn't satisfy what ts-jest requests
remote: ➤ YN0060: │ @groupic/api@workspace:packages/api provides ts-loader (p40b23) with version 8.1.0, which doesn't satisfy what webpack-graphql-loader requests
remote: ➤ YN0002: │ @groupic/common@workspace:packages/common doesn't provide @types/qs (pce84e), requested by twilio
remote: ➤ YN0002: │ @groupic/gql@workspace:packages/gql doesn't provide graphql (p7906e), requested by apollo-server-express
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide @react-native-community/masked-view (p1bce7), requested by @react-navigation/stack
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide react (pcc00c), requested by @react-navigation/native
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide react (pb47d6), requested by @react-navigation/stack
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide react (pb65fc), requested by react-native-safe-area-context
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide react-native (pe2840), requested by @react-navigation/native
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide react-native (p6b7eb), requested by @react-navigation/stack
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide react-native (pa0acb), requested by react-native-safe-area-context
remote: ➤ YN0002: │ @groupic/types@workspace:packages/types doesn't provide react-native-screens (p5e771), requested by @react-navigation/stack
remote: ➤ YN0002: │ @paljs/plugins@npm:2.11.1 doesn't provide graphql (p3e5f8), requested by graphql-tag
remote: ➤ YN0000: │ Some peer dependencies are incorrectly met; run yarn explain peer-requirements for details, where is the six-letter p-prefixed code
remote: ➤ YN0000: └ Completed in 0s 736ms
...
... lockfile diff results: https://ghostbin.co/paste/ku3mt
...
➤ YN0000: │
➤ YN0028: │ The lockfile would have been modified by this install, which is explicitly forbidden.
➤ YN0000: └ Completed in 3m 31s
➤ YN0000: Failed with errors in 3m 32s
```

Let me know if you need more information, and thank you in advance!

### Edit
~I forgot about `--immutable` – is there any way to instruct heroku to pass it?~
Added [validation results](https://ghostbin.co/paste/ku3mt) after noticing the inline diff for versions.