🚀 go-pugleaf

    Should one assume that if the package is a GNU package that gnu make is
    going to be required to make it?

No.

     others seem to
    depend on GNU make without specifying.

That's wrong; if it doesn't specify, then any make should work, and you
should report a bug.

    gcc -O -o regex  dregex.o printchar.o upcase.o xmalloc.o alloca.o test.o bsd-interf.o other.o tregress.o psx-basic.o psx-extend.o psx-generic.o psx-group.o psx-interf.o psx-interv.o main.o
    ld: Undefined symbol
       start
       _re_exec
       _re_comp
       .udiv
    ld: entry point not in text
    collect: /usr/bin/ld returned 2 exit status

Well, re_exec and re_comp should be in bsd-interf.o.  Are they (check
with nm)?  start and .udiv missing sounds like something is wrong with
the loader, but I'm afraid I wouldn't know where the problem might be.
Maybe gcc -v would help you isolate the problem.

   because the regex.info files were not rebuilt .

They shouldn't be rebuilt; the .info that come with the distribution
should be up-to-date.

    I cannot tell if I am having a package problem or if it has to do with a gcc
    or gnu make configuration problem.

I don't see anything that suggests the linking problem is due to GNU
make vs.  Sun's make ... it sounds like a gcc installation error in one
way or another, but that's just a guess.  (I didn't get the error with
SunOS 4.1.1/GCC 2.2.2/GNU make 3.62.)  I don't see anything else that
looks like an error.