The checksums for seamonkey-2.38.source.tar.xz are wrong. They must have replaced the original tar file upstream. Downloaded directly from mozilla, I get: :; sha256sum /usr/portage/distfiles/seamonkey-2.38.source.tar.xz da306b2fe5a38853b110a74af35332857d1b8aa034498983c1ec6f0b88706e5b /usr/portage/distfiles/seamonkey-2.38.source.tar.xz :; sha512sum /usr/portage/distfiles/seamonkey-2.38.source.tar.xz e1278489c5cc41e1cd87f4a01a7e5d16addea197ef5e04003459d7989bcf66a1d135f08dde7291227a9d556ad07928ed5f41d75d6e288bb68488ffd74a2657eb /usr/portage/distfiles/seamonkey-2.38.source.tar.xz :; sha1sum /usr/portage/distfiles/seamonkey-2.38.source.tar.xz fc9c22f7411372876d4f151ff6aca39cde31f711 /usr/portage/distfiles/seamonkey-2.38.source.tar.xz
It looks like the Manifest is broken, since it suggests the tarball is only ~80k in size: DIST seamonkey-2.38.source.tar.xz 83944 SHA256 8cbf01fca1763afb7cb1bde5330b0ed8b713a4b56a3113bfe7d9a8e02b202bef [...]
commit daa08c40d2a0819fd04f6236e8b095df301c9e0a Author: Lars Wendler <polynomial-c@gentoo.org> Date: Tue Sep 29 09:03:12 2015 www-client/seamonkey: Fixed Manifest (bug #561762). Package-Manager: portage-2.2.22 Signed-off-by: Lars Wendler <polynomial-c@gentoo.org>