I’ve just checked in support for the libRocket debugger:
rdb.name/librocket_debugger.png
You can enable it using rocketRegion.initDebugger() and then setDebuggerVisible(True).
It’s only available in a build with optimize level 3 and lower, so the standard SDK builds will contain support for it, but in the runtime build (if you pack your app as .p3d), initDebugger will not work and simply return false.
The change will be in tomorrow’s devel builds (assuming I didn’t make a mistake and the build succeeds) and also in the upcoming 1.8.1 release.