Hi,

This is fixed in the following commit:

https://git.savannah.gnu.org/cgit/guix.git/commit/?h=wip-ppc64le&id=ffcc950261c829e76f2faf6c8ea03d3fc56a20e1

The problem was in the config.log, but I didn't see it at first:

"powerpc64le-guix-linux-gnu-ld: cannot find -lstdc++"

Léo mentioned that it was probably a linking problem, and when I checked
his commits in his own Git repository, I found this, which solved the
problem:

https://gitlab.com/lle-bout/guix/-/commit/070e06e8be6090a7682288c24b5686f1b578c001

However, that commit would have changed the way we link gcc-final with
libstdc++ on all architectures.  I have made a similar change that
accomplishes the same thing, but only for powerpc64le-linux (or other
Guix system types beginning with "powerpc64").  On existing Guix system
types, we will continue to link the same as before.

Using commit ffcc950261c829e76f2faf6c8ea03d3fc56a20e1, I was successful
in building gcc-final. I'm closing this bug report.

-- 
Chris