Hi,

On 2020-11-26, gnulib-tests/Makefile.am was modified, so as to append
'-Werror' to the AM_CFLAGS, thus forcing the warning options chosen by
the GNU grep maintainer(s) on the GNU gnulib test code.

Meanwhile, it was mentioned several times on the Gnulib mailing list that
this is unsupported. E.g.
https://lists.gnu.org/archive/html/bug-gnulib/2023-08/msg00145.html

Still, in some circumstances, the current state of grep's
gnulib-tests/Makefile.am forces errors for warnings that the GNU grep
maintainer(s) are picky about and the GNU gnulib maintainers allow.

Please apply this patch, to respect the code ownership of Gnulib.

Thanks.