bundleignore doesn't ignore while copying files to temp dir

[anilanar]

Describe the bug
When there are files that have permissions incompatible with whatever yarn bundle does with them (or yarn/fslib does with them), adding such files to .bundleignore does not help because apparently ignoring happens later on in the pipeline.

In my case, I'm using nix + direnv, which creates a .direnv directory that contains symlinks to readonly files somewhere else on the system. Even if I add .direnv to .bundleignore, yarn bundle copies them to a temp dir and then runs chmod on them, which fails.

To Reproduce
Steps to reproduce the behavior:

1. cd into a project that uses yarn v2/v3 workspaces
2. touch ~/bar need a file somewhere else for this reproduction
3. sudo chown root ~/bar root or any other user, any user other than yours.
4. sudo chmod 0444 ~/bar make it readonly for everybody.
5. ln -s ~/bar foo gotta create a symlink for reproduction
6. Add foo to .bundleignore
7. cd into a workspace and run yarn bundle.

I think this can also be reproduced by creating a symlink to a non-existing path.

Expected behavior
Everything works fine.

Actual behavior
EPERM: operation not permitted, chmod '<omitted tmp dir path>/foo'

Desktop (please complete the following information):

• MacOS

Additional info
This could be solved by not even copying ignored dirs/files to a tmp dir for further processing.

[ojkelly]

Yep I think you're correct it's happening too late in the process.

The current process they're deleted after being copied to a tmp directory.

yarn.build/packages/plugins/plugin-bundle/src/commands/bundle/index.ts

Line 330 in 2f00066

exclude = await getExcludedFiles({

This can probably be solved by using something like fs-extra which has the ability to take in a function to filter files to copy
https://github.com/jprichardson/node-fs-extra/blob/master/docs/copy.md#copysrc-dest-options-callback

it would be replacing this line

yarn.build/packages/plugins/plugin-bundle/src/commands/bundle/index.ts

Line 286 in 2f00066

await xfs.copyPromise(tmpDir, sourceConfiguration.projectCwd, {

If this feels like something you might be able to work on let me know.