I [submitted](https://code.google.com/p/libproxy/issues/detail?id=206&thanks=206&ts=1395081017) them upstream.

The [Perl patch](https://trac.macports.org/browser/trunk/dports/net/libproxy/files/patch-bindings-perl-src-CMakeLists.txt.diff?rev=117895) seems MacPorts specific. We may have to do our own using `inreplace` or just not enable the Perl bindings.