Briefly, include $(wildcard ...) tries to include nonexistent files which makepp doesn't know how to build, which is contrary to the way $(wildcard) is documented to work in makepp.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
I'm trying to use an existing GNU Makefile with makepp, and hit an issue which I fully explain in this git repo:
https://github.com/scottj97/makepp-wildcard-issue
Briefly,
include $(wildcard ...)tries to include nonexistent files which makepp doesn't know how to build, which is contrary to the way$(wildcard)is documented to work in makepp.