libbluray and libudfread don't agree on (lib)udfread. Rename udfread.pc.in to libudfread.pc.in to reconciliate them.
$ pkgconf --print-provides udfread.pc udfread = 1.1.0
$ pkgconf --print-requires-private libbluray.pc libxml-2.0 >= 2.6 freetype2 fontconfig libudfread >= 1.1.0