Reported privately in email. I'll put it here to keep track easier:

Ubuntu 11.04

regarding the following output:
Package libgnomeui-2.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `libgnomeui-2.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libgnomeui-2.0' found
Package libgnomeui-2.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `libgnomeui-2.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libgnomeui-2.0' found

I resolved this by installing libgnomeui-dev:
sudo apt-get install libgnomeui-dev