Thanks I’ve found that discussion while searching before asking. The linked article is about include not lib, they’re quite different.
On the contrary, this is the ONLY place that people using Homebrew for productivity are allowed to ask questions by like minded developers. It’s a discussion, which is what forums are for. I say this with absolute certainty because the Homebrew bug tracker is intentionally strict and warns NOT to file bug reports. I’ve chosen StackOverflow as an alternate medium but only for the robots.txt (I rarely find community discussion when using search engines).
You can use this place to talk about Homebrew, ask for help or generally anything governed by our Code of Conduct that doesn’t fit on our GitHub repositories. Have fun!
Simply put, if behavior changed with cmake and Homebrew that’s been consistent for many, many years, it needs to be discussed in a medium somewhere. Telling someone that this ISN’T the place without offering an alternate discussion place dismisses the impact to the community – thus dismissing the purpose of a community chat <3.
If this is a nuance with Mojave, it would be nice to have some others help dig and offer information as to why so that projects relying on the old behavior – that valid since at least macOS 10.7 – can write suitable, permanent workarounds for projects.
Somehow, /usr/local/lib was automatically linked prior to Mojave.
Perhaps a better question to this community is… How does Homebrew do it? How does a homebrew .rb formula automatically look in Homebrew for linking at build time? Perhaps that’s the best permanent approach? The cmake formula maintainer may be able to help with this too. Linking Homebrew-provided libraries is very common for C++ projects and custom --prefix detection scripts make the build process more complex.
Finally, 3rd party products using CI services (like Travis-CI, Circle-CI, Jenkins etc) should be affected once they update to Mojave. That’ll probably be the time the majority of people complain. Many projects use Homebrew as dependency management but build on older environments for compatibility reasons.

