Trying to restart: A quick trip to Google took me on to a couple of articles - which described different problems, or OS Specific things.
Several referred to "Google Hell" on this subject, so let me add my own 2 cents worth in case you've arrived here from Google Hell!
I'm not sure why this line above didn't cause any issues with 5.1.55 and threw 5.1.56 into a frizzy...
This probably only applies if you are setting up My SQL via homebrew on your mac.
I ran the normal brew install mysql then found this error: ERROR! It turns out the solution was that I had missed part of the install instructions.
이미 그런 일을 벌였다면 문제를 일으키고 있는 로그 파일의 소유자를 mysql 을 구동하는 계정으로 만들어 줘야 한다.
만약 mysql 의 데이터 디렉토리가 /usr/local/mysql/data 라면 다음과 같이 해보자.