Problem: opatch fails with 'The patch directory area must be a number'
opatch failed with the above error.
Again its really a problem with the wetware (i.e. me), but worth typing up as its fairly obscure.
The problem seems to have been that I was logged in as a different user on the server which holds our staging area when I copied the software across. I mapped the drive on the the target server as the Oracle user, but it still seems to have inherited the wrong ownership at some level. I didn’t have much time to investigate so I can’t be 100% sure.