Conflicts with r-lib/actions/setup-r on macOS

[khaeru]

Describe the bug

In this workflow, we use both r-lib/actions/setup-r and setup-graphviz.

Recently the workflow began to error on macOS only; the key lines are:

==> Upgrading 1 dependent of upgraded formulae:
Disable this behaviour by setting HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK.
Hide these hints with HOMEBREW_NO_ENV_HINTS (see `man brew`).
r 4.2.1_3 -> 4.2.1_4
==> Downloading https://ghcr.io/v2/homebrew/core/r/manifests/4.2.1_4
==> Downloading https://ghcr.io/v2/homebrew/core/r/blobs/sha256:a5d64662b14c9669f3a58f1c6ad30982db60d681e299a5163780af6c313c3835
==> Downloading from https://pkg-containers.githubusercontent.com/ghcr1/blobs/sha256:a5d64662b14c9669f3a58f1c6ad30982db60d681e299a5163780af6c313c3835?se=2022-09-22T20%3A35%3A00Z&sig=zrLxcUkU1ehB8yeQmwlfdbuQC3MZZNZILZVDE%2B4IpJs%3D&sp=r&spr=https&sr=b&sv=2019-12-12
==> Upgrading r
  4.2.1_3 -> 4.2.1_4 

==> Pouring r--4.2.1_4.big_sur.bottle.tar.gz
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink bin/R
Target /usr/local/bin/R
already exists. You may want to remove it:
  rm '/usr/local/bin/R'

To force the link and overwrite all conflicting files:
  brew link --overwrite r

To list all files that would be deleted:
  brew link --overwrite --dry-run r

Possible conflicting files are:
/usr/local/bin/R -> /Library/Frameworks/R.framework/Resources/bin/R
/usr/local/bin/Rscript -> /Library/Frameworks/R.framework/Resources/bin/Rscript

To Reproduce

Steps to reproduce the behavior:

# In an action

jobs:
  job-name:
    steps:
    - uses: r-lib/actions/setup-r@v2
    - uses: ts-graphviz/[email protected]

Expected behavior

Both are installed and usable on the job runner.

I was able to work around the error by reversing the order: setup-graphviz before setup-r. Usability would be better if the actions were not sensitive to order.

[kamiazya]

@all-contributors please add @khaeru for bug, research.

[allcontributors]

@kamiazya

I've put up a pull request to add @khaeru! 🎉