and (and my own recent pain) were caused by .gitignore files included in the logstash 1.4.x releases.
My reading of those two cases is that they were resolved by the user removing one or more .gitignore files themselves.
Others are likely to fall into this hard-to-debug bear trap in future. The tar balls contains many .gitignore files.
I suggest that your release process be modified to exclude all .gitignore files from the releases.