Unfortunately forking a popular bot can be very difficult.
The issue is that the bot's entire database is cloned when forking, and this requires no connected users to that database.
Perhaps try forking a less popular bot.
I will also look into creating a template for brain bot, templates cannot be accessed by users, so do not have the forking issue.
Why do you want to fork Brain Bot? What are you looking for exactly?
Note that all bot's can answer "What is" type questions, Brain Bot uses the default scripts, he just has a large amount of corrected responses.
I am also looking into adding a shared repository of chat logs, so you would be able to import a chat log containing everything that Brain Bot has learned.