I think I figured out the problem. When I run `make -d`, I see problems like:
Prerequisite `m4/extern-inline.m4' is newer than target `aclocal.m4'. Must remake target `aclocal.m4'. Apparently it doesn't like the fact that I modified extern-inline.m4 more recently than aclocal.m4. I have never run into this problem before. I wonder if I can add a line to the patch to trick it into updating aclocal.m4. I would be fine with doing it manually, but I am working on a build system (kind of like Homebrew) that does everything behind the scenes.
