ENV: fix homebrew_extra_pkg_config_paths

[ilovezfs]

Switch to HOMEBREW_LIBRARY since HOMEBREW_LIBRARY_PATH already includes
"/Homebrew" and HOMEBREW_LIBRARY is less confusing.

Closes Homebrew/homebrew-core#3038.

[ilovezfs]

@MikeMcQuaid this fixes a regression introduced by a02be9e

By the way, this is at least the second time this same thing has happened probably because the variable name is "backwards."

[xu-cheng]

We probably should avoid to use HOMEBREW_LIBRARY_PATH at all, which is intended to refer to the ruby load path.

As it would be help for readability and avoid misunderstanding, if we only keep HOMEBREW_LIBRARY and remove HOMEBREW_LIBRARY_PATH.

[DomT4]

👍 to Xu's comment. Let's try to get this shipped out fairly quickly, leaving things like this broken for longer than discovered is extra pain for us & users.

[ilovezfs]

PR refreshed.

[DomT4]

LGTM. I personally wouldn't bother to wait for CI on this one, but up to you.

[ilovezfs]

Ran test-bot locally, and it's fine of course

[UniqMartin]

Thanks for the fix! I agree that the similarity between HOMEBREW_LIBRARY_PATH and HOMEBREW_LIBRARY can cause confusion and thus lead to subtle bugs like these. I'm not sure we can eliminate the former completely, as HOMEBREW_LIBRARY_PATH and HOMEBREW_LIBRARY/"Homebrew" are very different things during brew tests. But we can at least try to find a better name.

Unfortunately, HOMEBREW_LOAD_PATH is already taken and is a list of paths during testing, so cannot be used as a substitute for HOMEBREW_LIBRARY_PATH. Does HOMEBREW_CODE_PATH sound reasonable?

[MikeMcQuaid]

Sorry for the pain, folks.

Thanks for the fix! I agree that the similarity between HOMEBREW_LIBRARY_PATH and HOMEBREW_LIBRARY can cause confusion and thus lead to subtle bugs like these. I'm not sure we can eliminate the former completely, as HOMEBREW_LIBRARY_PATH and HOMEBREW_LIBRARY/"Homebrew" are very different things during brew tests. But we can at least try to find a better name.

Agreed.