autoconf-2.66 broken - how to combat?

[Dewey Hylton <dewey.hylton%gmail.com@localhost>]

it appears as if autoconf-2.66 is broken, and a preliminary patch is available 
for types.m4

sourced from this thread:
http://lists.gnu.org/archive/html/autoconf/2010-07/msg00006.html

this will get sorted out on its own. my question has to do with how to 
temporarily combat the issue. very much like the poster in the original thread 
message, i am seeing this:

cd /tmp/pkgsrc/databases/mysql5-client/work/mysql-5.0.91 && autoconf && 
autoheader
aclocal.m4:16: warning: this file was generated for autoconf 2.63.
You have another version of autoconf.  It may work, but is not guaranteed to.
If you have problems, you may need to regenerate the build system entirely.
To do so, use the procedure documented by the package, typically `autoreconf'.
configure.in:1929: error: AC_CHECK_SIZEOF: requires literal arguments
../../lib/autoconf/types.m4:765: AC_CHECK_SIZEOF is expanded from...
configure.in:1929: the top level
autom4te: /opt/pkg/bin/gm4 failed with exit status: 1

i don't understand what i'm seeing here. the complaint relates to types.m4 
under lib/autoconf ... i have exactly one types.m4 on my system, and it's 
nowhere under a directory called lib. i patched the one that i do find, but 
continue to get the same exact error. so i believe this particular types.m4 is 
being extracted from somewhere else during this process, and only kept 
temporarily. if i'm right, from where does it come and how do i patch to get 
around this issue while awaiting a newer autoconf?

i'm not a dev, so i realize this may be a rediculously simple question for 
others. thanks.