Hi,

I've the same issue when building for i686 from an x86_64 computer with
the following commands:
> guix build -s i686-linux fakeroot

The log is in zdjf6dkagsmlrrimm6nsz8p3xkxpx3-fakeroot-1.30.1.drv.gz
(attached).

And:
> guix build --target=i686-linux-gnu fakeroot
The log is in yscc2h0g7n3jbjz163g2p2layhm5wm-fakeroot-1.30.1.drv.gz
(attached).

For some reasons fakeroot is also pulled with:
> guix system image \
> <-s i686-linux|--target=i686-linux-gnu> \
> -t raw-with-offset system.scm

On x86 raw-with-offset is used for computers with BIOS interfaces.

Denis.