Workspace changes don't seem to be detectable by wmctrl

[mbert]

If I want to bind actions to workspace change events (like setting wallpapers by workspace using feh), these events should be detectable by the usual tooling for this. I tried wmctrl, but it failed to catch anything. I am not deeply familiar with the window manager standards relevant for this stuff, maybe I need to use another tool for this, nevertheless seems worth mentioning.