For test cases, see bug #5061 (on build-appliance) Another test-case, test Hob on commit 432294856418fc40e749552106034b8e14fa5c81. On this commit Hob hangs on sanity checks because it receives a bb.command.CommandFailed after "findConfigFilePath" is triggered. It will be good to show some errors when this is happening. I think it requires some changes in bitbake.
patch merged to master: http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=fe3e26509da8d25fc5878f0a5d6d7ebaec54dbbf
Verified in master:65ca5cb1640901211746e812d9fbbe3daafb33b7.