No workspace switcher on Shell 3.37
Since building Shell 3.37.2 (and related Mutter, gjs etc.) from jhbuild, I am experiencing several small issues in the overview, such as broken "type to search" and esc keys and the workspace switcher appearing only as an empty box without thumbnails in it.
journalctl -xe seems to return this error every time I open the Overview, and which may likely be the cause of it:
gnome-shell[1784]: JS ERROR: TypeError: pspec is null
_easeActorProperty@resource:///org/gnome/shell/ui/environment.js:215:42
init/Clutter.Actor.prototype.ease_property@resource:///org/gnome/shell/ui/environment.js:280:9
_unshadeBackgrounds@resource:///org/gnome/shell/ui/overview.js:248:28
_animateNotVisible@resource:///org/gnome/shell/ui/overview.js:654:14
hide@resource:///org/gnome/shell/ui/overview.js:634:14
activateWindow@resource:///org/gnome/shell/ui/main.js:672:14
_onCloneSelected@resource:///org/gnome/shell/ui/workspace.js:1231:14
_activate@resource:///org/gnome/shell/ui/windowPreview.js:624:14
_init/<@resource:///org/gnome/shell/ui/windowPreview.js:244:51