Chris Marusich writes: > configure:6100: error: cannot compute sizeof (long long) It was mentioned on IRC that a better way to fix this would be to configure libstdc++ to install to /lib instead of /lib64, since in Guix we install libraries to /lib by convention, even on 64-bit systems. See: https://logs.guix.gnu.org/guix/2021-02-06.log I looked into this a bit more after that. It turns out that we do something like that already, in the original gcc package definition, for existing architectures. However, Léo pointed out that on the rs6000 architecture (i.e., powerpc), the gcc/config/rs6000 directory's build logic hard-codes some /lib64 references. I have added a phase that replaces those hard-coded references. I should also mention that I did try to use the --libdir configure flag to tell libstdc++ to install to /lib64, but it didn't work; libstdc++ just ignored the flag and still installed its libraries in /lib64. Replacing the hard-coded references fixed it, though. In addition, I discovered that the libstdc++ package does not actually re-use the package arguments from gcc. Therefore, it was necessary to add a similar phase in the make-libstdc++ procedure. Although it is possible that, to resolve this specific bug (gcc-final: "configure: error: cannot compute sizeof (long long)"), only the make-libstdc++ change is necessary, it seems prudent to go ahead and also make the change described above for gcc, to avoid future problems. I have pushed both changes to wip-ppc64le in commit db761a593992aea441055bda260461f4302a4667 on the wip-ppc64le branch. -- Chris