docbook and postgresql

Hi folks

I'm trying to build the documentation for pgsql (so that I can change
it for the stuff we are building) and I'm having trouble finding the
necessary docbook stuff.

I looked at:

http://developer.postgresql.org/docs/postgres/doc-build.html

checking for onsgmls... onsgmls
checking for openjade... openjade
checking for DocBook V3.1... yes
checking for DocBook stylesheets... /usr/share/sgml/docbook/
checking for sgmlspl... sgmlspl

I set my DOCBOOKSTYLE to /usr/share/sgml/docbook

However, I don't seem to have anything that looks like nwalsh-modular
in my system (the example in the above web page). As a result I get
this:

sailesh:datafix>~/work/postgres/doc/src/sgml: cd
sailesh:datafix>~: cd work/postgres/
sailesh:datafix>~/work/postgres: cd doc/src/sgml
sailesh:datafix>~/work/postgres/doc/src/sgml: gmake admin.html
/usr/bin/perl /usr/share/sgml/docbook//bin/collateindex.pl -f -g -t 'Index' -o bookindex.sgml -N
Can't open perl script "/usr/share/sgml/docbook//bin/collateindex.pl": No such file or directory
gmake: *** [bookindex.sgml] Error 2
sailesh:datafix>~/work/postgres/doc/src/sgml:

So, sorry for the newbie question, but if somebody could point me to
what exactly I need to install, given that configure thinks that I do
have docbook-3.1, I'd be obliged. Thanks !

--
Pip-pip
Sailesh
http://www.cs.berkeley.edu/~sailesh