gnome-system-tools-2.14.0 fails to build with LDFLAGS="-Wl,--as-needed" because it puts the local libsetuptool.a after the main GST_LIBS, which then get stripped out by --as-needed. The patch reorders them, however, it's done in configure.in and I'm not sure if this is the best place to do it, so it might be best to ask flameeyes to check over it if he's got time. Patch to follow.
Created attachment 84202 [details, diff] gnome-system-tools-2.14.0-as-needed.patch
The patch works fine over here.
Works for me too (binutils-2.16.92, LDFLAGS="-Wl,-O1 -Wl,--as-needed -Wl,--sort-common").
Fixed in CVS. Thanks for the patch.