Locating header file error

Hi, I am trying to enable ipset feature in unbound hence added BuildRequires: pkgconfig(libmnl) and added enable-ipset to the config However I am getting an error from the obs saying it can't find it "checking for libmnl... configure: error: Could not find libmnl, libmnl.h" by looking at the libmnl-devel package the header is there and ipset is using the same library with no problems. How do I find the problem point and possibly fix it ? Thanks