Dealing With Automatic Provides/Requires and Filtering
%{?scl:%filter_from_requires s|pkgconfig|%{?scl_prefix}pkgconfig|g}
This is only an example, but probably we need to notice user that
filering must be done carrefully, not using a too large criteria: you
can requires a pkgconfig(foo) from system and a pkgconfig(bar) from the scl.
Need also some proposal about the libraries, when the provided soname
exists in the system which can create awful dependencies issues.
Remi.