apt-0.5.15lorg2-alt52 How to reproduce -- with an uninstalled package which changed between the apt-get-updates: apt-get remove tmux apt-repo rm sisyphus && apt-repo add p6 && apt-get update Start apt-shell (in another terminal) and don't close it. apt-repo add sisyphus && apt-repo rm p6 && apt-get update In apt-shell, do: install tmux commit It aborts like this: apt> install tmux apt> commit The following NEW packages will be installed: tmux 0 upgraded, 1 newly installed, 0 removed and 4 not upgraded. apt-shell: rpm/rpmhandler.cc:119: virtual std::__cxx11::string RPMFileHandler::Directory(): Assertion `HeaderP != __null' failed. Aborted A solution would be either for apt-shell to lock APT's data preventing any other instances re-writing it (but not reading it), or for apt-shell to re-read the data if it has changed. Another case -- out of curiosity -- if the package list hasn't changed at all between the apt-get-updates: Start apt-shell (and leave it running). [root@ovicaa apt]# rm /var/cache/apt/*.bin /var/lib/apt/lists/*ftp.alt* -vi rm: remove regular file ‘/var/cache/apt/pkgcache.bin’? y removed ‘/var/cache/apt/pkgcache.bin’ rm: remove regular file ‘/var/cache/apt/srcpkgcache.bin’? y removed ‘/var/cache/apt/srcpkgcache.bin’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_noarch_base_pkglist.classic’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_noarch_base_pkglist.classic’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_noarch_base_release’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_noarch_base_release’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_noarch_base_release.classic’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_noarch_base_release.classic’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64_base_pkglist.classic’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64_base_pkglist.classic’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64_base_release’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64_base_release’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64_base_release.classic’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64_base_release.classic’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64-i586_base_pkglist.classic’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64-i586_base_pkglist.classic’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64-i586_base_release’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64-i586_base_release’ rm: remove regular file ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64-i586_base_release.classic’? y removed ‘/var/lib/apt/lists/ftp.altlinux.org_pub_distributions_ALTLinux_Sisyphus_x86%5f64-i586_base_release.classic’ [root@ovicaa apt]# apt-get update In apt-shell, do: apt> install tmux apt> commit The following NEW packages will be installed: tmux 0 upgraded, 1 newly installed, 0 removed and 1602 not upgraded. Need to get 0B/232kB of archives. After unpacking 608kB of additional disk space will be used. Do you want to continue? [Y/n] n E: Operation cancelled. apt> It doesn't abort. Another case is a curious one, too -- what if the lists change, but the wanted package doesn't: apt-repo rm sisyphus && apt-repo add p7 && apt-get update Start apt-shell. apt-repo rm p7 && apt-repo add t7 && apt-get update In apt-shell, do: apt> install tmux apt> commit The following NEW packages will be installed: tmux 0 upgraded, 1 newly installed, 0 removed and 173 not upgraded. apt-shell: rpm/rpmhandler.cc:119: virtual std::__cxx11::string RPMFileHandler::Directory(): Assertion `HeaderP != __null' failed. Aborted So, the change of the package is not essential. (http://packages.altlinux.org/en/Sisyphus/srpms/tmux tells us that tmux is the same in p7 and t7.)