After rm /var/cache/apt/*.bin apt-cache started to work. (the files were pkgcache.bin and srcpkgcache.bin and they were restored after running apt-cache search ls :>)
-- [feisty] apt and aptitude crashing https://launchpad.net/bugs/73062 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
