Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|--- config.def.h.orig	2020-11-12 20:23:48.867954750 +0100
|+++ config.def.h	2020-11-12 20:21:15.055922720 +0100
--------------------------
Patching file config.def.h using Plan A...
Hunk #1 succeeded at 276.
Hunk #2 succeeded at 344.
done