Well, on Windows we bundle always the latest available GTK version in MSYS2. Currently, this is GTK 2.24.32 with GLib 2.56.2.
I was just able to reproduce it, though it took me a couple of attempts to trigger it. Unfortunately, the gdb prompt doesn't react on Ctrl-C to interrupt the process and get a backtrace :(. Also, there were no related GTK warnings or other output on stdout/stderr.