Copyartifact 1.34 includes this commit: https://github.com/jenkinsci/copyartifact-plugin/commit/f5647fcb445c83b1cfc80d83801be41e774e3770

s3-plugin consumes this symbol, in current git master: https://github.com/jenkinsci/s3-plugin/blob/master/src/main/java/hudson/plugins/s3/S3CopyArtifact.java#L176