I've also experienced the same problem today as I tried to upgrade to mysql-server-5.1 5.1.63-0+squeeze1.
I've managed to debug the postinstall script and the problem was caused by the line 144: bash /usr/bin/mysql_install_db --rpm 2>&1 | $ERR_LOGGER I didn't had the time to look very deeply in this script, but at least I could install mysql-server-5.1 properly by substituting the previous line with this: bash /usr/bin/mysql_install_db --user mysql --rpm 2>&1 | $ERR_LOGGER Another option is to edit /usr/bin/mysql_install_db and put user="mysql" in the line 30. So you can avoid this issue in future upgrades also. I hope this can help. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org