I investigated a fedora bugreport last night and found that handling of the "Conflicts" tag is pretty broken in current pkg-config and can lead to segfaults. I've put my fix in https://bugs.freedesktop.org/show_bug.cgi?id=13265 The original Fedora bugreport is here: https://bugzilla.redhat.com/show_bug.cgi?id=384421 Matthias