building docs fails for stable ghc-6.4.2 (2006/03/23 snapshot)

I built yesterday's ghc-6.4.2 snapshot (2006/03/23) and had a problem
building the docs.

I used XMLDocWays=html in my mk/build.mk

I was building with make -j2.

I am using:
libxslt-1.1.15
libxml-1.8.17
docbook-xsl-stylesheets-1.68.1

Here's the tail of the build log:

------------------------------------------------------------------------
==fptools== make all -wr --jobserver-fds=3,11 -j;

in /var/tmp/portage/ghc-6.4.2_pre20060323/work/ghc-6.4.2.20060323/docs/building
------------------------------------------------------------------------
rm -f -rf building/
/usr/bin/xsltproc --stringparam base.dir building/ \
            --stringparam use.id.as.filename 1 \
            --stringparam html.stylesheet fptools.css \
            --stringparam toc.section.depth 3 --stringparam
section.autolabel 1 --stringparam section.label.includes.component.label
1   \
            /usr/share/sgml/docbook/xsl-stylesheets-1.68.1/html/chunk.xsl 
building.xml
building.xml:4525: parser error : Opening and ending tag mismatch:
emphasis line 4469 and sect2
</sect2>
        ^
building.xml:4554: parser error : expected '>'
    ; always useful to have a log around
    ^
building.xml:4554: parser error : Opening and ending tag mismatch:
command line 4553 and comm
    ; always useful to have a log around
    ^
building.xml:4559: parser error : Opening and ending tag mismatch: para
line 4547 and programlisting
    ; then tar up, unpack where wanted, and enjoy</programlisting>
                                                                  ^
building.xml:4560: parser error : Opening and ending tag mismatch:
listitem line 4547 and sect2
</sect2>
        ^
building.xml:4561: parser error : Opening and ending tag mismatch:
itemizedlist line 4536 and sect1
</sect1>
        ^
building.xml:4565: parser error : Opening and ending tag mismatch: para
line 4535 and article
</article>
          ^
building.xml:4566: parser error : Premature end of data in tag sect2
line 4528

^
building.xml:4566: parser error : Premature end of data in tag para line
4468

^
building.xml:4566: parser error : Premature end of data in tag sect2
line 4443

^
building.xml:4566: parser error : Premature end of data in tag sect1
line 4258

^
building.xml:4566: parser error : Premature end of data in tag article
line 5

^
unable to parse building.xml
make[2]: *** [building/index.html] Error 6
make[1]: *** [all] Error 1
make[1]: Leaving directory
`/var/tmp/portage/ghc-6.4.2_pre20060323/work/ghc-6.4.2.20060323/docs'
make: *** [build] Error 1