Few weeks ago I’ve found interesting bug with Ruby 2.3 and Rails 22.214.171.124. One of my pet projects is too old (haha) and I’m using Rails 126.96.36.199. After system updating to the latest MacOS Sierra, and rbenv with Ruby 2.3, my project starts with exception. Calling any relation raises very strange error:
no implicit conversion of nil into String
After some googling I’ve found that troubles in the my current version of Active Record.
Linked Github issue.
So you can update your Rails to the 188.8.131.52 or use this initializer:
class Hash undef_method :to_proc if self.method_defined?(:to_proc) end