Please describe the problem:
Even when given --enable-gtk-doc=no to configure, the installation fails

Steps to reproduce:
run configure on a system without gtkdoc
run make
run make install


Actual results:
...
-- Installing ./html/gstreamer.devhelp
which: no gtkdoc-rebase in (/usr/bin:/bin)
make[5]: *** [install-data-local] Error 1
make[5]: Leaving directory `.../gstreamer-0.10.21/docs/gst'
make[4]: *** [install-am] Error 2
make[4]: Leaving directory `.../gstreamer-0.10.21/docs/gst'
make[3]: *** [install] Error 2
make[3]: Leaving directory `.../gstreamer-0.10.21/docs/gst'
make[2]: *** [install-recursive] Error 1
make[2]: Leaving directory `.../gstreamer-0.10.21/docs'
make[1]: *** [install] Error 2
make[1]: Leaving directory `.../gstreamer/src/gstreamer-0.10.21/docs'
make: *** [install-recursive] Error 1
gstreamer: make install failed


Expected results:
no error

Does this happen every time?
yes

Other information: