When playing minecraft for awhile, my .minecraft folder will fill up with output-client.log and output-client.log.lck which will then be sequentially numbered. It usually creates about 20 files per day. The only way to get around this was by creating a .command file to run at startup which contains 'sudo find /Users/Alex/Library/Application\ Support/minecraft -name ".log" -delete'
Duplicate of MC-9779, please use the search function to see if your bug has already been submitted. Currently over 58% of tickets are being closed as duplicate.