Fail to build wich cxxstd=20 on Clang about locale HOT 6 OPEN

I don't see how that issue is still relevant; it was fixed as of LLVM 15, and we're past that.

Looks I misinterpreted the error message which also started with "Undefined symbols" and seemingly related to std::basic_string<char8_t> and I missed the important part in all those templates: "typeinfo for char8_t" is what is missing.

And indeed I've seen that before popping up with libc++ on FreeBSD. I fixed that for the upcoming release. You can use that or apply c5e8f02 as a patch.

from locale.

That is a known issue with Clang. Which version of clang and Boost are you using? In Boost 1.84 a workaround is implemented:

In Clang 15 this should be fixed.

from locale.

Thanks for the quick answer. We build Boost1.84 with Clang 16 on MacOs 10.9. I am not sure if the clang version on MacOs matches the LLVM's once though.

from locale.

They should match the LLVM 15.x version for a while already. So I'm not sure how to fix this from Boosts side. I'd say it should be fine to define BOOST_LOCALE_NO_CXX20_STRING8 on your side for this. If you have any information when/where this issue is fixed on MacOS and how to improve the condition to detect that I'd be grateful. Otherwise I'll just disable u8string support for MacOS completely.

from locale.

We're on clang 16 in conda-forge (though we could use clang 17 and soon 18 if we want; however libcxx is stuck at 16 pending some infrastructure work). The macOS deployment target in the PR mentioned by @sdebionne was already bumped to 10.13, and if there's a hard requirement to go higher, we can do that.

W.r.t.

I don't see how that issue is still relevant; it was fixed as of LLVM 15, and we're past that.

from locale.

I am not sure if the clang version on MacOs matches the LLVM's once though.

There's only the clang we provide ourselves, we never use the system(==image) compilers in conda-forge.

from locale.