A "necessary and sufficient" question on the use of .pc files supplied by library providers.

1. Package foo-devel installs a pkgconfig .pc file as a convenience to developers.
2. Package bar requires headers and libraries provided by foo and is both a build
    and runtime dependency of foo.
3. Package bar uses autotools and m4 to discover and test for the presence
    of foo.h and libfoo, but does not use not pkgconfig in any way.

True or False:

The spec for package bar MUST use BuildRequires: foo-devel and not 
BuildRequires: pkgconfig(foo), because bar does not use pkgconfig directly.

Ref: https://docs.fedoraproject.org/en-US/packaging-guidelines/PkgConfigBuildRequires/