Mina EC2 deployment saving cache issue

After deploy on a ec2 instance with mina i check the production log file and i faced with:

Warning. Error encountered while saving cache /home/ubuntu/bacana/tmp/build-1442877527942/tmp/cache/sass/d78f1e46c5027b7748b2f94fb1049a601a88a/jquery.dataTables.scssc: can't dump anonymous class #Class:0x007f1a650e

please, someone would explain what this mean?

obs: i'm using asset_sync!