Paul A. Patience schreef op ma 07-06-2021 om 00:37 [+0000]:
> +       (let ((out (assoc-ref %outputs "out")))
> +         `("CC=gcc"
> +           ,(string-append "X11PREFIX=" out)
> +           ,(string-append "X11BASE=" (assoc-ref %build-inputs "libX11"))
> +           ,(string-append "INSTALL_MAN1=" out "/share/man/man1")))

You should do

  `(,,(string-append "CC=" (cc-for-target))
    ,(string-append "X11PREFIX=" ...) ...)

to make sure cross-compilation will work.
(Try ./pre-inst-env guix build xkbset --target=aarch64-linux-gnu.)

Also, libx11 is usualy named "libx11" (no capital letters)
in package inputs, and very infrequently "libX11". I would use "libx11".

Greetings,
Maxime.