As reported in bug 401109 comment 3: It seems installing jpeg-8c-r1 causes a never-ending recursive revdep-rebuild: revdep-rebuild finds a bunch of libs broken following media-libs/jpeg installation, and proposes the following remeberge --oneshot: app-emulation/emul-linux-x86-baselibs:0 dev-lang/php:5.3 dev-python/imaging:0 media-libs/gd:2 media-libs/jpeg:0 After doing this, re-running revdep-rebuild causes the same result. I'm on amd64. I've seen this happen on all of my boxes, as far as I can see. They should all have the stable app-portage/gentoolkit-0.3.0.4-r5 installed.
jpeg's ebuild itself doesn't do anything special, no preserve_old_lib() usage in jpeg-8c-r1 (or any other jpeg version) also upgrade from jpeg-8b to jpeg-8c-r1 shouldn't trigger anykind of revdep-rebuild at all since the SONAME is always same, 8 so without futher information ... well, not much to do
ssuominen explained that this is by design when --library libjpeg.so.8 is passed to revdep-rebuild. I had assumed that it would only rebuild conditionally.
Updated revdep-rebuild documentation to reflect that --library will unconditionally emerge packages that use the named library. http://git.overlays.gentoo.org/gitweb/?p=proj/gentoolkit.git;a=commit;h=04e5656fe2f8b93b28ebb716275f10d8061cd45f
The revdep-rebuild changes were released in gentoolkit-0.3.0.5
