app-arch/lbzip2-2.0 and 2.1 produces CRC error on decompressing on amd64 systems using glibc-2.14 It can be reproduced like this: lbzip2 -cd portage-20111125.tar.bz2 | md5sum (freetype-2.4.8.tar.bz2 for example cannot be decompressed, too) It looks like it was identified: https://github.com/kjn/lbzip2/issues/4 ...but lbzip2-2.1 (2.0 too) is involved and should be masked. (I can see it is ~amd64 ;-)
Already fixed in -r1.