Tor Browser silently fails to start if gtk2 is not installed
more annoyingly, this issue can only be diagnosed by running
Browser/start-tor-browser simply output nothing.
I downloaded stock Firefox ESR 52.8.0 and ran it with
-P non_default_profile -no-remote and it started with no issues. it comes with both "libmozgtk.so" and "gtk2/libmozgtk.so" which I assume helps.