Installation af gtk 2 temaer

Jeg kan ikke finde ud af at installere gtk2 temaer, som jeg downloader. Jeg har installeret gtk+2.0 fra Debian unstable.

Når jeg kører ./configure kommer dette:

checking for gtk+-2.0 >= 2.0.0... Package gtk+-2.0 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gtk+-2.0.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gtk+-2.0' found
configure: error: *** GTK+-2.0 not found; GTK2 theme engine will not be build