compile error in contrib/xml2

Hi,

I'm trying to compile the CVS version of contrib/xml2 for
postgresql-7.4.2. I'm hitting that error:

[bertheau(at)dicaprio pgxml2]$ gcc -fpic -c xpath.c -I`pg_config --includedir-server` `pkg-config libxml-2.0 --cflags`
xpath.c: In function `xpath_table':
xpath.c:653: error: `work_mem' undeclared (first use in this function)
xpath.c:653: error: (Each undeclared identifier is reported only once
xpath.c:653: error: for each function it appears in.)

I haven't found a declaration of work_mem anywhere in /usr/include/pgsql
- what am I doing wrong?

--
Markus Bertheau <twanger(at)bluetwanger(dot)de>