That could probably be called a Heisenbug[0]: A bug that disappears or alters its behavior when one attempts to probe or isolate it. Though it depends on the c

That could probably be called a Heisenbug[0]: A bug that disappears or alters its behavior when one attempts to probe or isolate it. Though it depends on the cause - as others in this comment chain said, if it's just that the file isn't actually being updated between tests, but adding a new line forces an update/recompile/etc., I'm not sure what you'd call it. [0] http://www.catb.org/~esr/jargon/html/H/heisenbug.html http://www.catb.org/~esr/jargon/html/H/heisenbug.html