[xml] make install problems on HPUX

[Thomas Porschberg <thomas porschberg osp-dd de>]

I tried to install libxml2-2.4.18 on HPUX with gcc.
1)./configure --prefix=/usr/local --with-zlib=/opt/zlib --without-python 
  --enable-fast-install=no --without-html-dir

2) make
3) make tests (all fine)
4) make install

./structure.gif ./DOM.gif ./smallfootonly.gif ./redhat.gif ./libxml.gif ./w3c.png no/libxml2-2.4.18/html
        /opt/imake/bin/install -c -m 0644 ./html/*.html no/libxml2-2.4.18/html
        /opt/imake/bin/install -c -m 0644 ./html/index.sgml no/libxml2-2.4.18/html
        (cd ; gtkdoc-fixxref --module=libxml --html-dir=no)
sh: cd: The specified directory is not valid.
sh: gtkdoc-fixxref:  not found.
*** Error exit code 127 (ignored)
Making install in example
Making install in python
Making install in .
        /bin/sh ../mkinstalldirs 
Make: Don't know how to make install-data-local.  Stop.
*** Error exit code 1

Stop.
*** Error exit code 1

Stop.
*** Error exit code 1

Stop.

Has anybody a idea what's wrong here ?