yum update gave me about 130 packages to update (mostly connected with upgrading from GNOME 3.8 to 3.14 on Scientific Linux 7). I installed the updates, which went fine, but after logging off, the computer hung. Rebooting also hung around the initialization of gnome. I booted into run level 3, used yum history undo to revert, and got the computer up and running again.
Whenever I have had this problem before, it has been video driver related, but this laptop uses the default drivers packaged with scientific Linux, and since I don't need to reinstall them for kernel updates, I don't see why I would need to now (and wouldn't know how).
My question is then in two parts. One, is there a way to find out specifically which of the 130 updates is causing the crash by looking at logs? If not is there a simple way to pick out packages, installing them one by one, to sort this out? I don't know how to get to the bottom of the dependency tree, so that I am only installing a couple at a time. Every time I tried to cherry pick one package, it had 20-30 dependencies and I didn't feel like trying all 130 to find the bottom by hand.