On Thu, Jan 9, 2020 at 1:51 PM Andrii Kolomoiets <andreyk.mad@gmail.com> wrote:
> Here is the '~/emacs-crash.el' content:
> (make-frame `((parent-frame . ,(window-frame))))
> (make-frame `((parent-frame . ,(window-frame))))
> (make-frame `((parent-frame . ,(window-frame))))
> (make-frame `((parent-frame . ,(window-frame))))
> (delete-frame)
> (delete-frame)
> (delete-frame)
> (delete-frame)
> (garbage-collect)

That sounds like Robert's bug, but not like the one that's related to
the "x = false" thing.

Can you try the attached patch?