$ LC_ALL=C guix describe
Generation 92   May 21 2020 23:54:36    (current)
  guix 1ce1583
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 1ce1583186578deffa119b056ba977d795f52691
$ guix environment -n --fallback -s armhf-linux --pure mes
The following derivations would be built:
   /gnu/store/7wyllvjhz39zlwbjyl801kwc8lgnaxyy-profile.drv
   /gnu/store/555qdvkb4qzxw7y7y78ibis6q29nd11i-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.5.0.drv
The following profile hooks would be built:
   /gnu/store/62i0pnic6ajgpnfld7qqx4dql3vnaqq7-info-dir.drv
   /gnu/store/jb59nr76vvbpx3mshmfk6h15dv5hbmnx-xdg-desktop-database.drv
   /gnu/store/x4byvngyb4y80v8p146rv1cgmcf8dk38-manual-database.drv
   /gnu/store/yqn9akjwsh0dv1q2fvfi45kl604787jx-xdg-mime-database.drv

Why is gcc-cross-sans-libc-i686-unknown-linux-gnu in the list even though there
is a conditional to prevent it from being there?

>       ,@(let ((target-system (or (%current-target-system)
>                                  (%current-system))))
>            (cond
>             ((string-prefix? "x86_64-linux" target-system)
[...]