So, if it is intentional - then it is working as designed (you may want to add a check for gmake then), otherwise - the way "non-gnu make(s)" handle the '[' character "break things".
Now, running /opt/bin/make (to be sure!) at the pain point I see:
GEN man/sum.1
GEN man/sync.1
GEN man/tac.1
GEN man/tail.1
GEN man/tee.1
GEN man/test.1
GEN man/timeout.1
GEN man/touch.1
GEN man/tr.1
GEN man/true.1
(Note: GEN man/test.1 is suppossed to be visible as white text with a blue background - just in case)
I, personally, am happy enough that I can run the configure command without gmake being installed (as that also requires gnu.gettext to be loaded and I am trying to avoid an unneeded dependency on gettext. I want to be specifically aware of the dependencies. And as often as it requires I will just build in phases.)
Many thanks again.