Each time I switch between build configurations (e.g. Debug and Release), a new "Parsing C/C++ Files" task is added to the list of tasks in the bottom right corner. This unnecessarily uses a lot of memory. After waiting for a while (could be 5 minutes), these tasks eventually disappear.

This only started happening after I upgraded Qt Creator and didn't use to happen for example in version 4.12.1, so this seems to be a regression.