Hello Samuel, The problem was that guix was using gcc-4.9 for cross-compiling which has a bug not present in newer versions. Using the newer gcc-5 fixes this. [1]
Now I only have problems with linking http://paste.lisp.org/display/330765 Has anyone encountered this before? Thank you, Manolis [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63567