Re: git: 56aaed388b0a - main - Merge libcxxrt master fd484be8d1e94a1fcf6bc5c67e5c07b65ada19b6

From: Dimitry Andric <dim_at_FreeBSD.org>
Date: Sat, 19 Mar 2022 19:52:00 UTC 
On 18 Mar 2022, at 15:10, Antoine Brodin <antoine@freebsd.org> wrote:
> 
> On Wed, Mar 9, 2022 at 7:46 PM Dimitry Andric <dim@freebsd.org> wrote:
>> 
>> The branch main has been updated by dim:
>> 
>> URL: https://cgit.FreeBSD.org/src/commit/?id=56aaed388b0a177b9defb4e6ecb8a716abb3cf33
>> 
>> commit 56aaed388b0a177b9defb4e6ecb8a716abb3cf33
>> Merge: 2ea6414ed8bb 672085f2aef2
>> Author: Dimitry Andric <dim@FreeBSD.org>
>> AuthorDate: 2022-03-09 19:45:01 +0000
>> Commit: Dimitry Andric <dim@FreeBSD.org>
>> CommitDate: 2022-03-09 19:45:01 +0000
>> 
>> Merge libcxxrt master fd484be8d1e94a1fcf6bc5c67e5c07b65ada19b6
>> 
>> Interesting fixes:
>> 47661d0 Match libc++abi/libsupc++ when demangling array types
>> e44a05c Fix unitialized variable in __cxa_demangle_gnu3 after #6 (#8)
>> 5088b05 Remove some code duplication.
>> fd484be Atomics cleanup (#11)
...
> After this merge, some i386 c++ processes are hanging.
> For instance:
> http://gohan05.nyi.freebsd.org/data/main-56aaed388b0a-default-foo/2022-03-17_16h07m06s/logs/errors/tbb-2020.3_4.log
> http://gohan05.nyi.freebsd.org/data/main-56aaed388b0a-default-foo/2022-03-17_16h07m06s/logs/errors/poppler-qt5-21.12.0.log
> http://gohan05.nyi.freebsd.org/data/main-56aaed388b0a-default-foo/2022-03-17_16h07m06s/logs/errors/kf5-kdoctools-5.91.0.log
> http://gohan05.nyi.freebsd.org/data/main-56aaed388b0a-default-foo/2022-03-17_16h07m06s/logs/errors/kf5-kguiaddons-5.91.0.log

I could reproduce a CMake hang with poppler-qt5, and it turns out that
libcxxrt's https://github.com/libcxxrt/libcxxrt/commit/fd484be can make
__cxa_guard_acquire hang on i386.

I reverted the upstream commit in:
https://cgit.freebsd.org/src/commit/?id=2548237983c47c61601b883bb9d6c9a803ef8ce4

Can you please retry after this?

-Dimitry