unfortunately. For instance, libxcb's xcb.pc declares:
Requires.private: pthread-stubs ...
Thus libxcb has to declare the pthread-stubs package as a
propagatedBuildInput, otherwise packages that check for libxcb using
pkg-config (such as libX11) will fail. But then we get a totally
unnecessary additional runtime dependency, which is clearly a bad
thing.
svn path=/nixpkgs/branches/stdenv-updates/; revision=13058
