Compat packages and pkgconfig & cmake provides

[Richard Shaw]

NOTE: This is part of the ongoing saga that is the OpenEXR project. As of
2.5.5 IlmBase was absorbed into the main OpenEXR library, and then with 3.x
imath was split out as a standalone library.

I've built openexr2 since many packages don't support openexr 3.x. I also
set openexr2-devel to conflict with openexr-devel since they should not be
installed at the same time. The project either supports OpenEXR 3 or it
doesn't.

The question is I'm currently renaming the pkgconfig and cmake modules to
have a "2" at the end. This makes specifying which one in a spec file easy,
but this could mean having to patch the build systems of the projects that
use it.

Does it work, and/or is it acceptable to put a less than version
requirement? I.e,

BuildRequires: pkgconfig(IlmBase) < 3

In the spec file instead? This would be much easier.

Thanks,
Richard