`glibcLocales.override` forces rebuild of all packages?

Hi,

The size of glibc-locales package is 214MB on x86_64-linux. I’m trying to trim it down with glibcLocales.override { allLocales = false; }, leaving only en_US.UTF-8 enabled. However, nix build --dry-run shows a long list of rebuild. That would certainly wastes power, bandwidth and even more disk space.

Is there any other way around? I just want to trim down the locales.