Why is this perl checking code not working for me?

[Dr. David Kirkby]

I'm trying to check if the version of perl is at least x.y.z

I found a macro with this syntax.


AX_PROG_PERL_VERSION([VERSION],[ACTION-IF-TRUE],[ACTION-IF-FALSE])

http://www.nongnu.org/autoconf-archive/ax_prog_perl_version.html

The documentation says one needs to run AC_CHECK_PROG or AC_PATH_PROG 
first, so $PERL is set to the path to perl. But it keeps failing on me:

AC_PATH_PROG([PERL],[perl])
AX_PROG_PERL_VERSION([5.8.0],[],[])





checking for perl... /usr/local/bin/perl
checking for a sed that does not truncate output... /opt/csw/bin/gsed
checking for grep that handles long lines and -e... /usr/sfw/bin/ggrep
./configure: line 4836: syntax error near unexpected token 
`$ax_perl_version,le,$perl_version,'
./configure: line 4836: ` 
AX_COMPARE_VERSION($ax_perl_version,le,$perl_version,'


Am I overlooking something obvious, or is the macro broken?

Dave