/etc/locales.gen is not persisting.

[mikemol]

Or, at least, I expect it isn't. In any case, I'm seeing this message from the installation of sys-libs/glibc:

• Generating all locales; edit /etc/locale.gen to save time/space

Locale configuration is hardcoded into the script, so either it's not being written properly, or it's getting overwritten by, e.g. dispatch-conf.

[mikemol]

Actually, looks like it's just a typo. The script is writing /etc/locale.gen, not /etc/locales.gen