xscrnsaver build error on Ubuntu 9.04

[Brian Pitts <brian polibyte com>]

I built gnome shell successfully a few weeks ago, but my attempt at
updating today failed. I tried installing libxcb-screensaver0-dev but
this didn't help. The error message is below:

checking for MUTTER_PLUGIN... configure: error: Package requirements
(gtk+-2.0 dbus-glib-1 metacity-plugins gjs-gi-1.0 xscrnsaver
libgnome-menu  gconf-2.0 gdk-x11-2.0 clutter-x11-0.9 clutter-glx-0.9)
were not met:

No package 'xscrnsaver' found

Consider adjusting the PKG_CONFIG_PATH environment variable if you
installed software in a non-standard prefix.

Alternatively, you may set the environment variables MUTTER_PLUGIN_CFLAGS
and MUTTER_PLUGIN_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.

make: *** [config.status] Error 1


All the best,
Brian Pitts