Linux-ci actions fail for macos-13 gcc builds with linker assertion failed

[jhmgoossens]

Recent builds of Linux-ci fail for the macos-13 gcc, while the macos-13 clang builds work OK, and all other linux builds (ubuntu) are OK as well.

The logs (below) indicate an assertion failed with the linker "ld: Assertion failed: (resultIndex < sectData.atoms.size())"
This seems to be related to https://forums.developer.apple.com/forums/thread/737707
and Homebrew/homebrew-core#145991
These pages suggest the workaround CXXFLAGS='-Wl,-ld_classic'

I cannot explain why this has started to happen the last few months only. The Xcode 15 version (15.1) included in the macos-13 images was update in DEC 2023 to 15.1 and hasn't changed since, as far as I can tell.

I'm not very familiar with the linux-ci / coinbrew builds.
How can we add the suggested CXXFLAGS?
Shall we add this workaround for the macos-12 CC=gcc linux-ci matrix entry?

The logs seem to suggest this issue starts in CoinUtils, but because the remaining projects are not built, the same could also happen for subsequent projects.

2024-03-04T16:07:09.5826290Z ##################################################
2024-03-04T16:07:09.5827480Z ### Building CoinUtils master 
2024-03-04T16:07:09.5828910Z ##################################################
2024-03-04T16:07:09.5829670Z 
2024-03-04T16:08:59.2882820Z 0  0x10d4c7f43  __assert_rtn + 64
2024-03-04T16:08:59.2901910Z 1  0x10d3c9f43  ld::AtomPlacement::findAtom(unsigned char, unsigned long long, ld::AtomPlacement::AtomLoc const*&, long long&) const + 1411
2024-03-04T16:08:59.2903980Z 2  0x10d3e6431  ld::InputFiles::SliceParser::parseObjectFile(mach_o::Header const*) const + 19745
2024-03-04T16:08:59.2905930Z 3  0x10d3f6b71  ld::InputFiles::parseAllFiles(void (ld::AtomFile const*) block_pointer)::$_7::operator()(unsigned long, ld::FileInfo const&) const + 657
2024-03-04T16:08:59.2907480Z 4  0x7ff80a0f2066  _dispatch_client_callout2 + 8
2024-03-04T16:08:59.2908250Z 5  0x7ff80a10518f  _dispatch_apply_invoke_and_wait + 213
2024-03-04T16:08:59.2909040Z 6  0x7ff80a104692  _dispatch_apply_with_attr_f + 1207
2024-03-04T16:08:59.2909740Z 7  0x7ff80a104847  dispatch_apply + 45
2024-03-04T16:08:59.2911830Z 8  0x10d48f972  ld::AtomFileConsolidator::parseFiles(bool) + 370
2024-03-04T16:08:59.2912820Z 9  0x10d416d67  main + 12263
2024-03-04T16:08:59.2913950Z ld: Assertion failed: (resultIndex < sectData.atoms.size()), function findAtom, file Relocations.cpp, line 1336.
2024-03-04T16:08:59.2915190Z collect2: error: ld returned 1 exit status
2024-03-04T16:08:59.2915830Z make[2]: *** [libCoinUtils.la] Error 1
2024-03-04T16:08:59.2917480Z make[1]: *** [all] Error 2
2024-03-04T16:08:59.2926890Z make: *** [all-recursive] Error 1

[jhmgoossens]

To answer one question:
The proposed flags can be added in the linux-ci.yml as
flags: CC=gcc-13 CXX=g++-13 OSX=13 ADD_CXXFLAGS=-Wl,-ld_classic
See CoinUtils PR218
Now the linker internal error does not occur.

[jhmgoossens]

This issue can be closed. The workaround CC=gcc-13 CXX=g++-13 OSX=13 ADD_CXXFLAGS=-Wl,-ld_classic is in place in all relevant actions. Let's review this in OCT 24 to see if the ADD_CXXFLAGS=-Wl,-ld_classic is still required for macos-13 builds.