Update

Author: LukasAud

lib/puppet/parser/functions/load_module_metadata.rb

@@ -24,7 +24,11 @@ module Puppet::Parser::Functions
 
     metadata_exists = File.exists?(metadata_json) # rubocop:disable Lint/DeprecatedClassMethods : Changing to .exist? breaks the code
     if metadata_exists
-      metadata = JSON.parse(File.read(metadata_json))
+      if Puppet::Util::Package.versioncmp(Puppet.version, '8.0.0') < 0
+        metadata = PSON.load(File.read(metadata_json))
+      else
+        metadata = JSON.parse(File.read(metadata_json))
+      end
     else
       metadata = {}
       raise(Puppet::ParseError, "load_module_metadata(): No metadata.json file for module #{mod}") unless allow_empty_metadata