At the moment the default option is to run a mock build on the package.
Since this is the most basic requirement I think that we should just stop the review if the mock build fails.
This could always be compensated by the --nobuild option
Start on http://git.fedorahosted.org/git/?p=FedoraReview.git;a=commit;h=57e2d7e3b08fbe9b8234af137554cf0f61a408e7
Finished on http://git.fedorahosted.org/git/?p=FedoraReview.git;a=commit;h=c97a27a2f13575adb3b448339a85f7fec2e5bdbf