Use Homebrew's std_cmake_args

[jlaxson]

Among several things, this explicitly passes the correct Xcode sysroot to cmake and on to clang. Without it, can spuriously get failure to find system symbols similar to these issues: https://stackoverflow.com/questions/58628377/catalina-c-using-cmath-headers-yield-error-no-member-named-signbit-in-th

I don't know the rhyme or reason to why it works sometimes (e.g. magnum from this repo worked for me, but magnum-plugins didn't).

[mosra]

Ohhhh so that's the solution, thanks! ❤️

And I can tell you why the problem happens -- I did a full investigation not so long ago: https://doc.magnum.graphics/magnum/platforms-macos.html#platforms-macos-troubleshooting-build-mysteriously-fails

Hum and I see some new issues related to SPIRV-Tools, gotta investigate (if you know what changed in that package, please share!).

[jlaxson]

I'm not sure what the difference is, I'm on Mojave same as the circle image and it is working fine for me from a fresh reinstall of spirv-tools and magnum-plugins. But, when I look at the cmake code it installs, nothing actually does add_library(SPIRV-Tools), only SPIRV-Tools-shared and similar. I think it's a bug in spirv-tools - they have that target as an alias internally, and try to export it, but cmake doesn't export/install aliases. Still no clue why it works for me.

I do notice that the brew tap in the circle config doesn't actually check out the branch under test, not sure how intentional that was. I think you'd want a manual fetch/reset to the appropriate ref, or use the circle checkout command explicitly rather than homebrew's command.

[jlaxson]

Also there is a note at the top of the install step re: unshallowing the homebrew clones, don't know if that means it's getting a different version of the formula than I have

[mosra]

But, when I look at the cmake code it installs, nothing actually does add_library(SPIRV-Tools), only SPIRV-Tools-shared and similar.

Now I remember -- that's it. I was aware of this change and just put it aside "for now". Seems like that commit got released, so I have to account for that in my Find module.

I do notice that the brew tap in the circle config doesn't actually check out the branch under test

Yes, good point -- is there a way to make homebrew use a certain branch of the tap? (I assumed there was no way and so I usually "tested" by pushing straight to master.)

[jlaxson]

I think ^(think) you could replace run: brew tap mosra/magnum with

checkout:
  path: /usr/local/Homebrew/Taps/mosra/homebrew-magnum

Which will use circle's logic to get the right code and put it where homebrew is looking.

[mosra]

Yes, but I'm afraid this kind of a hack might hide issues that would happen only with brew tap.

Or I guess I could brew tap on master and do this on other branches, that could be sufficiently bulletproof.

[mosra]

Ok, the spirv-tools issue got fixed worked around in mosra/magnum-plugins@d8d016e (it's actually an issue with spirv-tools own cmake being totally broken, so I had to patch get_target_properties() to not die with a fatal error when that happens).

I restarted the PR build, but got greeted by

[ 15%] Linking CXX executable ../../Release/bin/magnum-bullet
Undefined symbols for architecture x86_64:
  "btDiscreteDynamicsWorld::stepSimulation(float, int, float)", referenced from:
      Magnum::Examples::BulletExample::drawEvent() in BulletExample.cpp.o

so I suppose that's another fresh exciting breakage in a 3rd party dependency. Investigating...

[mosra]

Bullet package breakage fix submitted as Homebrew/homebrew-core#68634, with additional work done in mosra/magnum-integration@c9f9a0d & mosra/magnum-integration@8585e34 to turn linker errors into something more meaningful. Waiting until the package update happens, then will finally merge this.

[mosra]

Seems like it did the job, I don't need any workarounds to build magnum-plugins anymore. Magic.

In 4020b83 I made the change to check out a branch as you suggested and it works well. Thanks for that as well :)

[jlaxson]

# What kind of INSANE language is this?!

Story of my life