[Bug bootstrap/87858] Building old multilib bootstrap GCC: stage1 32-bit libstdc++ fails to build after building 64-bit libstdc++

["mkrupcale at matthewkrupcale dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87858

--- Comment #12 from Matthew Krupcale <mkrupcale at matthewkrupcale dot com> ---
I've updated the patch to include the target libstdc++ path on LD_LIBRARY_PATH
only after stage1 for both host and target module exports--that is, previously,
the patches only modified the LD_LIBRARY_PATH exports for target modules,
whereas the new version does the same for host modules as well. This fixes an
issue I found while building GCC 7 on RHEL 9 in which the gotools host module
failed to build with similar ABI issues as described in this thread.

See my copr repos [1,2] for both GCC 7 and 8 now both building with the
respective patches on multiple OS (RHEL 9, Fedora 37, 38), architectures
(aarch64, ppc64le, s390x, x86_64), and host GCC versions (11.3, 12.2, 13.0).

(In reply to Libor Bukata from comment #4)
> We also cannot build older GCC versions with GCC 11 nightly (commit
> 8a6a62614a8ae) on Solaris Trunk:
> ...
> 
> GLIBCXX_3.4.29 is a new addition to libstdc++.so.6 that is not available in
> older libstdc++.so.6 libraries of GCC 7, 9, and 10.

Without the patches, I did also observe the issue Libor Bukata saw in comment
#4 while building GCC 7 or 8 with GCC 11.

(In reply to Ed Gar from comment #9)
> I confirm that the issue persists even when using either patch suggested by
> Matthew Krupcale.

I was unable to reproduce your build issue with my patches.

[1] https://copr.fedorainfracloud.org/coprs/mkrupcale/gcc-7/build/5787271/
[2] https://copr.fedorainfracloud.org/coprs/mkrupcale/gcc-8/build/5798225/