Hi Don, I assume that it may be related to the cache based on Collections.synchronizedMap, the implementation is refined via using ConcurrentLinkedHashMap on parrot branch. Could you give it a try by following the steps?
$ git clone -b parrot https://github.com/apache/groovy.git $ cd groovy $ gradlew -PuseAntlr4=true jarAllAll ( then you can find the "groovy-all-2.5.0-SNAPSHOT.jar" file under directory target/libs ) Good luck :) Cheers, Daniel.Sun -- View this message in context: http://groovy.329449.n5.nabble.com/ConcurrentModificationException-with-use-of-memoize-tp5736788p5736805.html Sent from the Groovy Users mailing list archive at Nabble.com.