After updating Manjaro to the most recent stable release, gvim was opening in a tiny window, and I get the error:
(gvim:36266): Gtk-CRITICAL **: 19:54:37.038: gtk_distribute_natural_allocation: assertion ‘extra_space >= 0’ failed
I was not able to prevent the error from happening, but adding “winpos 0 0” to my .vimrc before I set the lines and columns fixed the tiny window issue. YMMV.
I feel like it was related to the fact that I tried to start gvim after the update was done but before rebooting. It’s as if some bad window state was saved somewhere, but I have not figured out where. At least it works.