GCC 9 linker error, missing GOMP_loop_nonmonotonic_dynamic_next

[Jakub Jelinek]

On Mon, May 06, 2019 at 02:41:41PM +0200, FX wrote:
> Hi gcc and gfortran developers,
> 
> While testing GCC 9.1.0 before shipping it as part of Homebrew for macOS, we’re seeing the following OpenMP-based failure when recompiling several software packages with GCC 9. It includes both C++ and Fortran codes, which were working fine with the exact same setup and GCC 8.3.0.
> 
> The missing symbols we’re seeing are always in this list:
> _GOMP_loop_nonmonotonic_dynamic_next
> _GOMP_loop_nonmonotonic_dynamic_start
> _GOMP_loop_ull_nonmonotonic_guided_next
> _GOMP_loop_ull_nonmonotonic_guided_start

Those are certainly exported from my GCC 9 libgomp.so.1.0.0 (at least on
Linux but I don't see how it could not be elsewhere).
So, the most likely explanation would be you are compiling something with
GCC 9, but linking against GCC 8 or earlier version of libgomp.

	Jakub