If you're willing to use a manifest, rather than the imperative package
management commands (install/upgrade/remove), then you can put your
package definition in a manifest file with the rest of your packages.
--8<---------------cut here---------------start------------->8---
(use-modules (gnu packages) (gnu packages base) (guix profiles))
(define my-glibc-locales
(make-glibc-utf8-locales
glibc
#:locales (list "cs_CZ" "en_GB" "en_US" "eo" "fr_FR" "ru_RU")
#:name "glibc-my-utf8-locales"))
(define packages
(specifications->packages
'("emacs"
"libreoffice"
;; ... Whatever other packages you want, as strings
)))
(packages->manifest (cons my-glibc-locales packages))
--8<---------------cut here---------------end--------------->8---
Then you can use "guix package --manifest=your-manifest-file.scm" to
make your system match what your manifest file declares.
Carlo