A lot of the aliases in /usr/share/X11/locale/locale.alias don't agree with the
system locales.  For example, eo is mapped to eo_XX.ISO8859-3, but the system
locale uses UTF-8:

$ LC_ALL=eo locale charmap
UTF-8

The locale eo_XX.ISO8859-3 doesn't actually exist.  Same problem for en_IN,
which is mapped to the non-existing en_IN.ISO8859-1, but the system locale uses
UTF-8.

C.UTF-8 is mapped to en_US.UTF-8, but the system locale is a separate locale.

Moreover, the file contains the same list twice, only with the first field
suffixed with a colon.