My Hudson lesson today: Hudson: Nothing to do and a FAILURE

I spent an hour tracking down a build job failure after a migration. The build job in Hudson checked out every required source from two Git repositories, but then it finished with a FAILURE return code. Weird. The very same job in the same configuration worked yesterday evening successfully and the source code in the Git repository didn't change in the meantime. There was no commit at all!

After reading many times through the Hudson log I found a small hint: 'Nothing to do'. Hmm, that didn't really help me. In a discussion with +Ralf Sternberg he came up with the idea to commit something to the Git repository in order to have a change there. I could not believe this, but gave it a try and, yes, my job run successful. Hudson seems to be very intelligent in this case, probably too intelligent, and I didn't know how to interpret the message in the log file. I've opened bug 373753, maybe this can be improved.
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