gnome-shell 42 leaks tens of megabytes with every screenshot

gnome-shell leaks tens of megabytes with every screenshot. In my case always at least 30MB, sometimes up to 100MB, gets added to the resident set size of the gnome-shell process.

My screen is 3840x2160 so at 24bpp a screenshot would be 24.8MB, and at 32bpp it would be 33.1MB. Seems like too much of a coincidence that's the increment getting leaked with each fullscreen screenshot.

gnome-shell version 42.0-2ubuntu1