Also, should I try to uninstall and rebuild Scalar::Util?

Yes, I think so, and check that it's an XS build of Scalar::Util that gets installed. (I think it's dualvar() that needs the XS build.)

Hopefully that will take care of the Compress::Zlib error, too. But this is a problem that I've never managed to reproduce, so I can't speak from personal experience :-)

Cheers,
Rob