Really Bad Game Freeze!
 

I just ran /script d(LibStub) and the game froze (also with LibStub:IterateLibraries()). Bad time. Couldn't view/switch to Task Mngr to kill it. Alt+F4 didn't work. Nothing worked, game stuck on screen, and couldn't close or move it to End Task. Only Win taskbar showed over it.

Finally, had use Winkey and "taskkill /f /im eso64.exe" to kill it. Flawless Fatality!

Probably a recursive / infinite loop. Not friendly for addon developers. :( Or is it just me?

LibStub is a table containing the table of every single library used by your addons. Frankly, I'd be surprised if outputting it provided anything of much interest. You should try doing /zgoo LibStub if you really need to see what's in it.

I've changed my approach already, avoiding this issue. I just figure this is a bug that affects addon dev's and shouldn't exist. I wonder if it'll be fixed with the paste limit crash bug with next major version update.