error compiling plperl

In trying to compile the plperl extension language for
postgres, i get the below error messages. i have not
been able to find where "errgv" and "na" are declared
nor what datatype they are.

is plperl "really" working? or is this just an experimental
sort of thing? has anyone gotten it to work successfully?

thanks
ed

plperl.c: In function `plperl_create_sub':
plperl.c:331: `errgv' undeclared (first use in this function)
plperl.c:331: (Each undeclared identifier is reported only once
plperl.c:331: for each function it appears in.)
plperl.c:337: `na' undeclared (first use in this function)
plperl.c: In function `plperl_call_perl_func':
plperl.c:447: `errgv' undeclared (first use in this function)
plperl.c:453: `na' undeclared (first use in this function)
plperl.c: In function `plperl_func_handler':
plperl.c:657: `na' undeclared (first use in this function)
plperl.c: In function `plperl_build_tuple_argument':
plperl.c:2195: `na' undeclared (first use in this function)
make: *** [plperl.o] Error 1