Almost all the hostRequires elements default to == if no op attribute is given, but in the latest version of beaker-job.rng the attribute is declared as mandatory which is inconvenient. It means submitting a perfectly valid hostRequires such as: <hostRequires> <cpu> <flag value="sse2"/> </cpu> </hostRequires> is met with a RELAX NG validation error.
http://git.beaker-project.org/cgit/beaker/commit/?h=develop&id=fd5b9d04dafc188620dbadfbc585be443343c33d
Beaker 0.11.0 has been released.