The headers for the current running kernel (latest yum update) were not found. ... The missing package can be probably installed with
yum install kernel-devel-2.6.38.6-26.rcl.fc15.x86_64
There are a few more messages and then more stuff happens with [OK] followed by
Installing graphics libraries and desktop service components
At which time the system deadlocks and there is no response to keyboard or mouse input. The only solution is to hard exit from VM by doing a machine power off.
Since I did do a system snapshot I go back to the point of after doing all the yum installs as indicated by the how-to-guide and try the yum install as indicated in the message. All I get is the package is not available.
I have been stuck on this Guest Additions install for a week now. Not very much fun.