cmake fails to build on Leopard 10.5: error: 'shared_mutex' is unavailable: introduced in macOS 10.12

[rmottola (Riccardo)]

I don't understand what fails, I attach the buildlog with clang 5, it fails also clang 7 as well with the default compiler.

[rmottola (Riccardo)]

build on 10.7 with clang 5

[kencu (Ken)]

Lots of errors, working on it.

PPC is a long way from fixed.

Even Intel might be trouble:

error: 'shared_mutex' is unavailable: introduced in macOS 10.12

for now, we're going to have to hang back to 3.15 on a number of systems...

[kencu (Ken)]

by the way, I think I've mentioned this to you before, but I do keep a reasonably up-to-date set of overlay repos for older systems that pegs (or fixes) these ports when I find them broken and unpegs them when we/I get around to fixing them in MacPorts. There's also a nice version of libsdl2 that works on 10.4 and 10.5 there.

​https://github.com/kencu/TigerPorts
​https://github.com/kencu/LeopardPorts
​https://github.com/kencu/SnowLeopardPorts
​https://github.com/kencu/LionPorts

[michaelld (Michael Dickens)]

cmake 3.18.0 builds cleanly for me on 10.5 PPC(32) using whatever compiler port selects. Please update the ports & see if this fixes the issue.

[rmottola (Riccardo)]

I just retried today it is version cmake-v3.19.1-64fb825438a2fecb9eab9933d5d1b926bf6f294b I tried on 10.5 Intel(64) and got this error again, did you fix something and the fix got lost? I build using clang-7. I actually wonder why I did not get this issue on 10.6 and 10.7 which I updated a couple of days ago, if the 10.12 message is correct

[rmottola (Riccardo)]

seems gcc7 works? strange!

[kencu (Ken)]

I think it has something to do with the __config header in the clang-7.0 libc++ headers. The availability is probably not set right for the new libcxx I install on Leopard i386.

I fixed that in newer clangs, but I think I never got around to backdating that fix to clang-7.0.

see <​https://github.com/macports/macports-ports/blob/master/lang/llvm-9.0/files/5005-MacPorts-only-patch-libcxx-includes-disable-availability-tests.diff>.