1. try to update packages from command line
2. fail because "Another app is currently holding the yum lock;"
3. service yum-updatesd stop
4. note that "Another app is currently holding the yum lock;" still.
5. ps ax |grep yum and note that yum-updatesd-helper is still running.
6. kill the pid
7. finally yum from the shell proceeds.
Indiscriminately killing the helper process is a good way to lead to hosed
rpmdbs if the user has configured yum-updatesd to automatically apply updates.
So just killing it is the wrong thing to do.
Maybe we should add a note to the shutdown command if the process is still locked.
So: if yum-updatesd is holding the yum lock output a 'process is running cannot
be shutdown safely' or somesuch message?
We've switched yum to retry if it encounters a held lock.