I might have found the reason thanks to "guix build -K". Here are a few files in the gcc source directory: lrwxrwxrwx 1 andreas users 9 Aug 20 22:29 gmp -> gmp-6.0.0 drwxr-xr-x 15 andreas users 4096 Aug 20 22:29 gmp-6.0.0/ lrwxrwxrwx 1 andreas users 9 Aug 20 22:29 mpc -> mpc-1.2.1 drwxr-xr-x 8 andreas users 4096 Aug 20 22:29 mpc-1.2.1dev/ lrwxrwxrwx 1 andreas users 10 Aug 20 22:29 mpfr -> mpfr-4.1.0 drwxr-xr-x 9 andreas users 4096 Aug 20 22:29 mpfr-4.1.0/
So it looks like gcc can cope with different gmp/mpfr/mpc version numbers, but not with the "dev" suffix. I will give it another try. Andreas
