This glitch is caused by wrong svn address. nano /var/lib/dpkg/info/w3af.postinst replace: svn co https://w3af.svn.sourceforge.net/svnroot/w3af/trunk w3af with: svn co https://svn.code.sf.net/p/w3af/code/trunk w3af apt-get upgrade if this doesn't solve your problem. Try the following method: aptitude remove se-toolkit aptitude purge se-toolkit aptitude clean aptitude autoclean git clone https://github.com/trustedsec/social-engineer-toolkit/ set/ cd set/ ./setup.py install This will help you install se-toolkit from a github source. then run: apt-get upgrade you shouldn't get any error.