Most likely I installed a package from world or universe that installs libpthread, e.g. native POSIX threads library. So with a plain bare ubuntu system this problem might not occur.
-- update from libc6-2.4-ubuntu10 to *-ubuntu12 fails https://launchpad.net/bugs/68389 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
