==> I have also filled it as a bug for SL 4.x in the bug tracking system, since there was no option for SL 4.2 there. Having just upgraded to SL 4.2 from SL 4.1 via yum upgrade, and wanted to use apt-get, I performed: [root@localhost download]# rpm -e apt-sourceslist-42-1.SL [root@localhost download]# rpm -Uvh ftp://ftp.scientificlinux.org/linux/scientific/42/i386/SL/RPMS/apt-sourceslist-42-1.SL.i386.rpm Retrieving ftp://ftp.scientificlinux.org/linux/scientific/42/i386/SL/RPMS/apt-sourceslist-42-1.SL.i386.rpm warning: /var/tmp/rpm-xfer.2k6qKj: V3 DSA signature: NOKEY, key ID a7048f8d Preparing... ########################################### [100%] 1:apt-sourceslist ########################################### [100%] [root@localhost download]# apt-get autoclean Reading Package Lists... Done Building Dependency Tree... Done [root@localhost download]# apt-get clean [root@localhost download]# apt-get update Get:1 ftp://ftp.scientificlinux.org 42/i386/apt release [1061B] Fetched 1061B in 2s (503B/s) Get:1 ftp://ftp.scientificlinux.org 42/i386/apt/os pkglist [1528kB] Get:2 ftp://ftp.scientificlinux.org 42/i386/apt/os release [104B] Get:3 ftp://ftp.scientificlinux.org 42/i386/apt/updates pkglist [14B] Get:4 ftp://ftp.scientificlinux.org 42/i386/apt/updates release [110B] Get:5 ftp://ftp.scientificlinux.org 42/i386/apt/contrib pkglist [81.0kB] Get:6 ftp://ftp.scientificlinux.org 42/i386/apt/contrib release [108B] Fetched 1116kB in 31s (34.9kB/s) Reading Package Lists... Done Building Dependency Tree... Done [root@localhost download]# apt-get dist-upgrade Reading Package Lists... Done Building Dependency Tree... Done You might want to run `apt-get -f install' to correct these. The following packages have unmet dependencies: gcc4-c++: Depends: libstdc++ (= 3.4.3) but 3.4.4-2 is installed Depends: libstdc++-devel (= 3.4.3) but 3.4.4-2 is installed libtool: Depends: gcc (= 3.4.3) but 3.4.4-2 is installed E: Unmet dependencies. Try using -f. [root@localhost download]#