Using SYSTEM_GCC=1 GCC_VERSION=7.3.0-15ubuntu2 ./buildall.sh to dodge #24, I get the following error trying to build automake:
GEN doc/aclocal-1.14.1
GEN doc/automake-1.14.1
help2man: can't get `--help' info from automake-1.14
Try `--no-discard-stderr' if option outputs to stderr
Makefile:3707: recipe for target 'doc/automake-1.14.1' failed
make: *** [doc/automake-1.14.1] Error 255
make: *** Waiting for unfinished jobs....
(That's the tail of check/automake-1.14.1.log.)