This code demonstrates how to steal an object from a caller somewhere up in the stack.

To demonstrate this, it mimics the handler() method of a BuildSRPMFromSCMTask object in a Koji builder process, calling callbacks implemented in plugins. The object the callback is interested in (which for some reason isn't accessible) is the created build root broot.

Running this would look like this (the build root id is random):

> ./kojid.py
BuildRoot(id=None) => id=19791
process_distgit_cb('postSCMCheckout', taskinfo={'method': 'buildSRPMFromSCM'}, *args=(), **kwargs={})
BuildRoot(id=19791).mock(args=['--shell', 'echo', 'We did it!'])
BuildRoot(id=19791).mock(args=['--buildsrpm', '...'])
>