Add the ability to dynamically link the system libc++ when installing Zig with a package manager on macOS

[utox39]

Hello there 👋
As reported in Homebrew/homebrew-core#210073 and #23127, Zig is built/linked incorrectly when you try to install it via Homebrew. This is because it is not possible to dynamically link system libc++ when using a package manager (e.g. Homebrew) for macOS.

For further context:
https://github.com/Homebrew/homebrew-core/pull/210173/files/8c652a274e6fda98b4ff8efe82b125af8344433b

https://ziggit.dev/t/linking-stage3-zig-dynamically-with-system-libc/5726

[alexrp]

@andrewrk why did 741445c also change macOS to use bundled libc++?

[andrewrk]

Sounds like you're thinking that exe.linkSystemLibrary("c++") is doing something different than exe.linkLibCpp(). It looks like that may be the case, but it's not intentional.

linkLibCpp() needs to gain logic to handle situations like this, such as choosing system-provided libc++ when targeting macOS. If it cannot detect such things automatically then it needs to be parameterized.

[theKnightsOfRohan]

As a stopgap, would it be possible to make the 13.0 release stay available on package managers? I noticed that Homebrew/homebrew-core#210173 is blocked, and for good reason, but making people be unable to install mac versions of zig from a package manager in the meantime seems untenable.

[andrewrk]

As a stopgap, would it be possible to make the 13.0 release stay available on package managers?

You are commenting on upstream's issue tracker. We have no say in this matter.

[theKnightsOfRohan]

Oh, my b. Sorry about that.

[zux0x3a]

I believe this issue is related to Homebrew not to Zig lang. installing zig from Mac ports with llvm19 fixes this issue.

[i0ntempest]

I believe this issue is related to Homebrew not to Zig lang. installing zig from Mac ports with llvm19 fixes this issue.

Because MP zig is statically linking libc++.