Pkgconfig files are meant to be common interfaces that all distros
share. Thus it is important that they are only modified upstream unless
we are really talking about trivial fixes like libsuffix support here.

If packagers don't follow this policy then they break this common interface.

This is not the first time happening because debian packagers
modify/rename/add pkgconfig files without caring about other distros
(e.g. libtbb-dev if I am not mistaken).

Developers running debian will code their build system believing that
"pkg-config --libs lua5.1" will be valid, but it's not, cause upstream
ships "lua.pc", not "lua5.1.pc".
Packagers from other distros will have to fix this once they want to
include the software from this developer.

Stop changing pkgconfig files randomly unless it's absolutely necessary.
Fix your lua packages in another way or send patches upstream.