Saving project settings for read only project

Hi!

I'm having following issue with PyCharm Community edition on Linux. I tried several versions available from JetBrains Toolbox, even the oldest one and the result is always the same.

Issue is as following. When I open a Python project from some read-only directory and try to mark it as excluded it disappears from the project view although "Show excluded files" is enabled. 

I mark directory as excluded as this was suggested to me in order to be able to save project setting for read-only project.

I think that directory marked as excluded should remain visible but instead it gets hidden. 

I also can't do "Save all" and project settings are not saved and it is suggested to restart PyCharm.

How to workaround the issue of not being able to save project settings for read only project? Even without marking directory as exclude?

Thanks.