I believe something needs to be done with the zlib-184.108.40.206-r1 and -r2
packages currently in the tree. The maintainer of zlib pushed those
revisions with a patch that alters macro identifiers, making Gentoo's
zlib incompatible with upstream. As a result, a lot of packages stopped
building. Bug reports for broken packages come in and then are being
modified to fit Gentoo's zlib.
Breaking compatibility with upstream zlib also means that non-portage
software, the ones I install with "./configure --prefix=$HOME/usr &&
make install", also won't build.
It's a mess right now and it just doesn't look right. The bug that
deals with it was locked from public view:
Is there a plan for this, or will we have to live with what is
essentially an incompatible Gentoo fork of zlib?