upstream has moved the source tarballs therefore the emerge fails Reproducible: Always
Created attachment 146902 [details] rsync-3.0.0_pre10
Created attachment 146904 [details] rsync-3.0.0_pre9
JFYI - the problem occurs if using the bootstrap method described in http://www.gentoo.org/proj/en/gentoo-alt/prefix/bootstrap-macos.xml and using the there mentioned bootstrap_prefix.sh script. Therefore it's before emerging subversion and doing a emerge --sync. IMHO it would be enough to actualize the tree extracted by ./bootstrap_prefix.sh $EPREFIX tree.
I updated to the officially released version and made a new snapshot.
... which means this issue has been fixed.