Unity 5.1 issue with UnityYAMLMerge

I had previously configured UnityYAMLMerge to work with P4V, and it worked brilliantly. I just upgraded to 5.1 and invoking it to handle a merge does… exactly nothing, as far as I can tell.

My theory is that the merge has unresolvable conflicts, and something is set up incorrectly with the fallback merge tool in mergespecfile.txt. However, P4V kindly does not show me anything about how it is attempting to invoke UnityYAMLMerge. Does the tool write a logfile anywhere that could help me untangle what’s going on under the hood, or do I need to run P4V with dtrace to have any hope of this?

The merge tool doesn’t have a log. You could try to get the 3 files to merge (base, mine, incoming) and execute the merge tool on the command line yourself. That may reveal what is going on.