Complex sentence: To measure software, it is often needed to alter it in some way, even if only in the memory of the computer, changing the behavior of the software itself, defects that are hard to detect for this reason got nicknamed heisenbug.
Split into simpler sentences: To measure software, it is often needed to alter it in some way, even if only in the memory of the computer, changing the behavior of the software itself. Defects that are hard to detect for this reason got nicknamed heisenbug.