Comment 0 for bug 336634

Carried over from the discussion on bug #3097.
Checking depencencies listed in the Requires.private field when performing
--exists effectively creates buildtime dependencies that are unnecessary for
pure dynamic builds.
For example, cairo now lists libpng12 in Requires.private, and every configure
script that tests for cairo now fails if libpng12.pc is not present, even though
libpng is not needed for all-dynamic linking.
Proposed solution: --exists should also ignore Requires.private unless --static
flag has been specified.