class ActiveRecord::FixtureSet::TableRow::PrimaryKeyError

def initialize(label, association, value)
  super(<<~MSG)
    Unable to set #{association.name} to #{value} because the association has a
    custom primary key (#{association.join_primary_key}) that does not match the
    associated table's primary key (#{association.klass.primary_key}).
    To fix this, change your fixture from
    #{label}:
      #{association.name}: #{value}
    to
    #{label}:
      #{association.foreign_key}: **value**
    where **value** is the #{association.join_primary_key} value for the
    associated #{association.klass.name} record.
  MSG
end