mustfail 'push is missing head ref update' +$push_spec2
mustfail 'pushing unexpected ref' $push_spec HEAD:refs/wombat
mustfail 'pushing multiple heads' $push_spec HEAD:refs/dgit/wombat
mustfail 'push is missing head ref update' +$push_spec2
mustfail 'pushing unexpected ref' $push_spec HEAD:refs/wombat
mustfail 'pushing multiple heads' $push_spec HEAD:refs/dgit/wombat