Arch Linux locale-gen tries to use /run/current-system

[Myles English <mylesenglish@gmail.com>]

Hello,

I am trying guix on Arch Linux.  While updating the system package to
glibc 2.23 I get this error:

$ locale-gen
Generating locales...
  en_GB.UTF-8...cannot create temporary file:
  /run/current-system/locale/2.22/locale-archive.nfq78F: No such file or
  directory

More info:

$ locale
LANG=en_GB.UTF-8
LC_CTYPE=en_GB.UTF-8
LC_NUMERIC="en_GB.UTF-8"
LC_TIME="en_GB.UTF-8"
LC_COLLATE="en_GB.UTF-8"
LC_MONETARY="en_GB.UTF-8"
LC_MESSAGES="en_GB.UTF-8"
LC_PAPER="en_GB.UTF-8"
LC_NAME="en_GB.UTF-8"
LC_ADDRESS="en_GB.UTF-8"
LC_TELEPHONE="en_GB.UTF-8"
LC_MEASUREMENT="en_GB.UTF-8"
LC_IDENTIFICATION="en_GB.UTF-8"
LC_ALL=

$ locale -a
C
POSIX

I don't understand why it is using /run/current-system/ because I am
using guix and not guixSD.  (I did try nix, just in case it matters for
this problem, but I think I have removed all references to it).

Does anyone know what I need to do to get locale-gen to run without an
error?

Thanks,
Myles