PATCH 10168386:R12.PO.B 12.1.3 - Libraries don't compile: 3-5961738731

Customer (Will Boudreau) applied PATCH 10168386:R12.PO.B - there are many Libraries don't compile - accross all applications.
Details are in adadmin_regen_forms2.log.

We had practically no invalids before the patch.
This was a fresh 12.1.3 install with a few one-off patches applied and was a stable environment.
Because so many forms/libraries from across the entire tech stack are broken, it looks like the patch changed some environment variable that affected how compilations work.
I'm going to manually recompile some libraries to get better error messages.

***********
Sample of one file with manual recompile - worked successfully:
-bash-3.2$ frmcmp_batch module=/u04/OraApps12i/ERPTEST/apps/apps_st/appl/au/12.0.0/resource/FNDATTCH.pll \