This was an interesting one, but surprisingly very easy to solve.
After installing the LUA tools as a plugin, Eclipse mysteriously stopped working: what happened was, I would launch Eclipse from a shortcut (I’m using Docky in Ubuntu 13.04, but as it turns out, this is irrelevant), it would show me a LUA development tools splash screen (weird), then the Eclipse workbench… and stop there.
I went on to launch Eclipse from the command line to see what was going on and… I discovered that somehow the eclipse binary had been swapped with another one called LuaDevelopmentTools. Funny thing was, the latter was actually the original eclipse binary. Also, eclipse.ini had been renamed to LuaDevelopmentTools.ini.
cd /path/to/eclipse/install/folder mv eclipse eclipse.bak mv LuaDevelopmentTools eclipse mv LuaDevelopmentTools.ini eclipse.ini mv eclipse.back LuaDevelopmentTools
restarted from the launcher, everything works.