https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112862
--- Comment #3 from Iain Sandoe <iains at gcc dot gnu.org> --- OK. So I realise the reason you see this and I wasn't: I have the habit of installing before running the testsuite. When I test uninstalled, then I get the issue. ... the subsequent work reveals that we are not setting the "ENABLE_DARWIN_AT_RPATH" in gcc/site.exp. Somehow an AC_SUBST has been dropped on the way. However, that is actually fixable with a small change to gcc/Makefile.in. ... then we have to add -Bpath/to/libatomic/.libs conditionally on ENABLE_DARWIN_AT_RPATH (in gfortran.exp) (not hard since ENABLE_DARWIN_AT_RPATH is a global) Now I have a concern that we have instances of -Bpath/to/libsomething/.libs that are present to allow for specs substitution and we also need them for providing run paths at test time. BUT, we do not want duplicates (since, that triggers a different warning for some Xcode versions, and is inefficient anyway - albeit probably a very minor contribution to testing time). So I think that gcc/lib/gfortran.exp needs to have the library -B/-L additions structured so that only one set gets added. I'll draft a patch for you to try.
