Ruby master ships with Psych 4.0.0 which makes YAML.load

defaults to safe mode (ruby/psych#487).

Keep compatibility by using unsafe_load.

From: settingslogic#21
Also: https://stackoverflow.com/a/71192990

lib/settingslogic.rb

@@ -100,7 +100,12 @@ def initialize(hash_or_file = self.class.source, section = nil)
       self.replace hash_or_file
     else
       file_contents = open(hash_or_file).read
-      hash = file_contents.empty? ? {} : YAML.load(ERB.new(file_contents).result).to_hash
+      hash = if file_contents.empty?
+        {}
+      else
+        payload = ERB.new(file_contents).result
+        (YAML.respond_to?(:unsafe_load) ? YAML.unsafe_load(payload) : YAML.load(payload)).to_hash
+      end
       if self.class.namespace
         hash = hash[self.class.namespace] or return missing_key("Missing setting '#{self.class.namespace}' in #{hash_or_file}")
       end