I'm happy to try, but I was not keeping a good log of my steps. I could grab my colleague's new Mac and do a better job if you'd like to work on that.
> What does the csrutil do?
Apparently it is System Integrity Protection. When I tried to this line from the steps at one of those links:
I got some message like "You are not allowed to do this." Not even with sudo. Searching the error message led to the suggestion to disable it. (But also to re-enable it after running that command.)
perl Makefile.PL MP_CCOPTS=-std=gnu89 ; make ; sudo make install