libgccjit and gccemacs

[Formbi]

Hello!

I'd like to make gccemacs work in Guix. Joseph LaFreniere made this libgccjit 
package:
https://debbugs.gnu.org/cgi/bugreport.cgi?bug=40045
and I made this: https://termbin.com/06cmr

When I try to build gccemacs, I'm getting errors like this:
ld: cannot find crtbeginS.o: No such file or directory
ld: cannot find -lgcc
ld: cannot find -lgcc
libgccjit.so: error: error invoking gcc driver

This seems to be connected to this problem:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87808
but I don't know how to fix this. I tried adding gcc-toolchain to inputs
of libgccjit and gccemacs, but it didn't help.