I was just running a standard Java file straight from Eclipse when I noticed something strange. The first line of output was not showing at all.

My code ran an analysis, got back a result and printed a couple of attributes from the result. I was getting all but the first line of output (even though I knew there was nothing wrong with the System.out.println code).

When I ran it in the terminal, I found a few hundred (or thousand) lines of debug output from the analyser which I had forgotten to disable. For some reason, Eclipse was ignoring this and only printing the remaining output. This consumed the first line too, for some reason.

As soon as I disabled the debug output from the analysis code, the output was behaving normally again.