> Would you mind giving a hint why one should not use mock from EPEL? Because the one in CentOS will, out of the box, pull out and properly configure the CentOS buildsys package, which itself is a meta-package whose dependencies are the minimal set required to create a chroot build environment: http://dev.centos.org/centos/buildsys/5/ My understanding (to be confirmed/infirmed by CentOS developers) is that this is the tool actually used to build CentOS. > Afaict the mock version in the CentOS repo is 0.6.13 which was released > years ago and the one in EPEL is 1.0.7 which is current. Yes, that's what I thought first as well, but the one from CentOS worked, while the one from EPEL did not (for the purpose of building CentOS RPMS => I don't say that EPEL's mock is broken). I tried to tweak it a bit, but in the end all that you need is a cleanly prepared chroot and the CentOS mock is good enough for that. (there is probably a way to get the EPEL one to work as well.) Hence the need to exclude the mock from EPEL in the repo file, otherwise it updates the one from CentOS.