OE fails with p4 command not found

From Openembedded

If you ever see something like the following:

Applying patch arm-thumb-mutex.patch
Get file ../dbinc/mutex.h from Perforce with lock? [y]
sh: p4: command not found
patch: **** Can't get file ../dbinc/mutex.h from Perforce

It probably means you have a P4* environment variable defined and GNU patch has assumed that you want to use perforce to find missing files, etc. Set the following environment variable to fix this issue:

export PATCH_GET=0