Ruby is expecting a Hash, but you forgot something (maybe a key name?)

Example:

# wrong
foo: { # Start of the new hash
  :bar # You're missing your key OR value
}

Either of these would work. The ruby error message says expecting => because your key/value pair in the hash is missing a key or a value, and => is the older hash rocket syntax.

# right
foo: {
  bar: :blah
}

# also right
foo: {
  :bar => :blah
}