Error: package requirements (gudev-1.0) were not met

[Alex Williams <linuxfpga gmail com>]

Hello!
I really want to improve network manager... I have real reasons to do that.
Now I've got latest sources from this git repo:
http://projects.gnome.org/NetworkManager/developers
When I trying to configure NetworkManager sources, I;m getting this error:

checking for DBUS... yes
checking for GLIB... yes
checking for GMODULE... yes
checking for GUDEV... configure: error: Package requirements
(gudev-1.0) were not met:
No package 'gudev-1.0' 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 GUDEV_CFLAGS
and GUDEV_LIBS to avoid the need to call pkg-config.
See the pkg-config man page for more details.

The problem is... I can't find any information about "gudev" and what
is it and where to get this?
My OS - Ubuntu 9.04 AMD64. No such package in repos.