"m4: memory exhausted" in aclocal

[Ethan Mallove]

Hello,

After consolidating a bunch of m4 in my configure.ac file
into AC_DEFUN's, I came across this error:

  m4: memory exhausted

I drilled down a bit and found the issue was an autom4te
call from aclocal. I pulled out the problematic autom4te
command and reran it using --debug, which revealed an
infinite loop in a new macro I had created from some
consolidated configure.ac code. Not sure how the inifinite
loop happened, but wanted to log the issue here for the next
person that runs into it.

  * SunOS 5.10 Generic_125100-04
  * aclocal (GNU automake) 1.10
  * autoconf (GNU Autoconf) 2.61
  * GNU M4 1.4.4

Cheers,
Ethan