$ LANG=fi_FI.utf-8 gimp {worked fine} $ LANG=eo_EO.utf-8 gimp (gimp:13217): Gtk-WARNING **: Locale not supported by C library. Using the fallback 'C' locale. $ LANG=eo_XX.utf-8 gimp (gimp:13228): Gtk-WARNING **: Locale not supported by C library. Using the fallback 'C' locale. $ LANG=eo.utf-8 gimp (gimp:13228): Gtk-WARNING **: Locale not supported by C library. Using the fallback 'C' locale. $ LANG=eo_.utf-8 gimp (gimp:13334): Gtk-WARNING **: Locale not supported by C library. Using the fallback 'C' locale. Ref: https://bugs.launchpad.net/ubuntu/+source/apt/+bug/560956
we don't have Esperanto locale in Fedora. But i also see its added to other distributions using patch. Try asking upstream to include Esperanto locale or maintainer of glibc can help you further here.
The upstream opinion on this topic is extremely clear: http://sourceware.org/bugzilla/show_bug.cgi?id=2135#c9 It's my opinion that Fedora should carry a patch anyway. Just as an example: GNOME has an active Esperanto translation community on track to official support (ie: over 80% translated) in the next release. But despite all the effort, it can't be used on Fedora...
also worth noting that yum lists a language support group: Esperanto Support [eo] that doesn't actually enable Esperanto support...
Locales are language/country pairs. AFAIK there is no EO country, so you'd need to ship not one, but > 130 eo_XX locales, that is complete nonsense. If you just want for whatever strange reason messages in esperanto, you can still use LANGUAGE=eo:fi:en LC_ALL=fi_FI.UTF-8 gimp or similar, gettext gives higher priority to the LANGUAGE variable over LC_ALL.
I was actually thinking that we could make a straight 'eo' locale, using relevant ISO standards as the "non-controversial" choices for the other categories. For example: - ISO 8601 for date/time (yyyy-mm-dd with 24 hour time) - ISO 14651 for collation - ISO 216 paper sizes (A4, etc.) - the ¤ currency symbol Numeric formats are slightly more difficult because ISO 31 specifies that either "." or "," is acceptable as a decimal separator. I'd appeal to POSIX in this case and go with ".".
You don't want an esperanto locale, you want esperanto message translations, which is what the LANGUAGE setting provides.
Setting LANGUAGE is not enough to get Esperanto message translations because there are strings mixed in with the locale as well such as the days of the week. Not everything in the locale is country-specific such as the collation order. I think most Esperantists would be happy with using an agreed standard for everything else (such the ISO standards mentioned by Ryan) because that is what you would have to use if you were speaking in an international context anyway, so most Esperantists would be used to it.