Hi Matt - back in 2015 (https://debbugs.gnu.org/cgi/bugreport.cgi?bug=19692, sorry for the delayed reply) you reported that your system failed the rm -f test.
For the next automake release, we've removed this test and tried to accept any rm. (More info: https://bugs.gnu.org/10828.) If you have a chance to try an automake pretest to confirm this (downloadable from https://alpha.gnu.org/gnu/automake-1.16j.tar.gz), that would be great. --thanks, karl.
