Configuring with -Werror used to work a while back for me; now that -Wno-unused-result has been fixed I gave it another try and got this:
configure: libxrandr 32-bit development files not found, XRandr won't be supported. configure: WARNING: Old Mesa headers detected. Consider upgrading your Mesa libraries. OpenGL and Direct3D won't be supported. configure: WARNING: No sound system was found. Windows applications will be silent.
After a quick investigation, turns out many configure checks produce warnings; patch below hacks around it, but I've never dealt with configure before and apparently fixes need to go in configure.ac -- anyone wants to give it a proper shot?
Sorry for the noise on wine-patches, this should have been gone here...
Patch looks ok, but that should only be changed in configure.ac... And the chance to get that in is not very high because AJ not always suppports different compilerflags.