Where to report a bug with XCompose files?

Originally asked on XCompose: How to disable default compose sequences? - Fedora Discussion

I’m a heavy user of the Compose key and have a custom ~/.XCompose file defining many compose sequences.

man xcompose says:

Compose files can use an “include” instruction. This allows local modifications to be made to existing compose files without including all of the content directly. For example, the system’s iso8859-1 compose file can be included with a line like this:

 include "%S/iso8859-1/Compose"

There are several substitutions that can be made in the file name of the include instruction:

%H expands to the user’s home directory (the $HOME environment variable)

%L expands to the name of the locale specific Compose file (i.e., “/usr/share/X11/locale//Compose”)
%S expands to the name of the system directory for Compose files (i.e., “/usr/share/X11/locale”)

For example, you can include in your compose file the default Compose file by using:

include "%L"

and then rewrite only the few rules that you need to change. New compose rules can be added, and previous ones replaced.

In practice, however, I’m finding that even when I have no include line, the default compose sequences do get used.

I don’t want this, because I wish to have a .XCompose that I can transport from one machine to another without wondering about the locale.

What library should I report this bug to?