Ok, it’s a bit finicky in trying to get it to crash. Could you perform a few random frustum selections / extraction attempts (i.e., delete the extraction and retry)? Sometimes it even crashes with just the selection and no extraction. I can confirm that it occasionally works for me as well, which smells like it depends on the type of selection. I’m currently unable to run on Linux… Could you try with a Windows build?
As a developer myself, I certainly appreciate a well written bug, so it’s only fair that I occasionally return the favor