fabpot/Twig — comment on commit 865a7039f8f93e0ad9e76c129481a0bbf9259aa3
File: lib/Twig/Environment.php line 108
By fabpot:

A template with a `dump` call in production is always a mistake.

Yes, it was moved out of core because I was not comfortable with it at that time (and I was right as this is now a function, not a tag). Also, note that the implementation is quite different. Furthermore, since then, I haven't found any better way to debug templates and as we are all using Twig on a day-to-day basis, I think everybody will acknowledge that this is actually really useful.