Comment # 52 on bug 1177260 from Richard Biener

(In reply to Egbert Eich from comment #51)
> (In reply to Richard Biener from comment #50)
> > Maybe you can just override LD?  OTOH to get libgfortran linked the link
> > probably uses FC, not CC, or does it explicitely add -lgfortran?  To me it
> > looks like an issue in the openblas makefiles.
> 
> It uses CC for linking - which points to gcc11 (on Leap/SLE) while FC which
> points to the stock gfortran is used to build the fortran sources. The
> latter may not be all that problematic, however, a binary may use other
> fortran libraries built with the stock gfortran compiler or be built/linked
> itself using this compiler.
> And, yes, the final link (done with $CC) adds -lgfortran.
> The problem is that we need to link C and Fortran objects together and make
> sure, the right libgfortran is used. I will try what happens if I naively
> set -lgfortran4. Likely, gcc11 will not find this library.

Of course not - it doesn't work this way.  You can link with the stock
gfortran compiler instead.  Note you possibly get ABI mismatches when
building with the stock gfortran but then link against the wrong library.

When you mix compilers you really should know what you are doing ;)