Package: libc6 Version: 2.7-3 Severity: grave The situation I got into was in process of upgrading libc6 and libc6-i686 from version 2.6.1-5 to 2.7-3. New libc6 was already unpacked and libc6-i686 was yet of old version. After that the system became totally unusable. Every exec ended up with sigsegv. Only removing /lib/i686 under another system's boot had helped.