brew upgradeしてmysqlが壊れたなら吹っ飛ばせば直る

# brew upgradeしたら壊れちまいやがった

```
$ mysql.server restart
 ERROR! MySQL server PID file could not be found!
Starting MySQL
.. ERROR! The server quit without updating PID file (/usr/local/var/mysql/GX1794.local.pid).
```

見事に使えなくなっています。
なんだかupgrradeした後のクラッシュはサポート対象外とかだそうで一旦ダウングレードとかして直してから再インストールが必要かとも思い、

```
$ brew postinstall mysql@5.7
==> Postinstalling mysql@5.7
==> /usr/local/Cellar/mysql@5.7/5.7.27_1/bin/mysqld --initialize-insecure --user=naoya.ohsaki --basedir=/usr/local/Cel
Last 15 lines from /Users/naoya.ohsaki/Library/Logs/Homebrew/mysql@5.7/post_install.01.mysqld:
2019-09-12 10:43:31 +0900

/usr/local/Cellar/mysql@5.7/5.7.27_1/bin/mysqld
--initialize-insecure
--user=naoya.ohsaki
--basedir=/usr/local/Cellar/mysql@5.7/5.7.27_1
--datadir=/usr/local/var/mysql
--tmpdir=/tmp

2019-09-12T01:43:31.093031Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2019-09-12T01:43:31.097131Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.
2019-09-12T01:43:31.097181Z 0 [ERROR] Aborting
```

ダウングレードしようにも落としてさえ来れない事態になっていました。

```
--datadir=/usr/local/var/mysql
```

## 解決策

・・・datadirのところ壊れちまったなら吹っ飛ばしてもいいんじゃ無いか？


そら、消えちゃえ。


```
sudo rm -rf /usr/local/var/mysql
```

それで、brew installを試みます。

```
brew install mysql
Updating Homebrew...
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
==> Updated Formulae
stone-soup

Warning: mysql: No available formula with the name "mysql-cluster"
'conflicts_with "mysql-cluster"' should be removed from mysql.rb.
Please report this to the homebrew/core tap!
==> Downloading https://homebrew.bintray.com/bottles/mysql-8.0.17_1.mojave.bottle.tar.gz
Already downloaded: /Users/naoya.ohsaki/Library/Caches/Homebrew/downloads/bb1858c9aac3410b34d4e12a593da4870efc76e9dba3f77d2a5923ac6f5f02dd--mysql-8.0.17_1.mojave.bottle.tar.gz
==> Pouring mysql-8.0.17_1.mojave.bottle.tar.gz
==> /usr/local/Cellar/mysql/8.0.17_1/bin/mysqld --initialize-insecure --user=naoya.ohsaki --basedir=/usr/local/Cellar/
==> Caveats
We've installed your MySQL database without a root password. To secure it run:
    mysql_secure_installation

MySQL is configured to only allow connections from localhost by default

To connect run:
    mysql -uroot

To have launchd start mysql now and restart at login:
  brew services start mysql
Or, if you don't want/need a background service you can just run:
  mysql.server start
==> Summary
🍺  /usr/local/Cellar/mysql/8.0.17_1: 284 files, 272.4MB
```

ハハハハハハハハ、動くじゃ無いか。手こずらせやがって。

```
$ mysql --version
mysql  Ver 8.0.17 for osx10.14 on x86_64 (Homebrew)

$ brew services start mysql
==> Successfully started `mysql` (label: homebrew.mxcl.mysql)

$ ps aux | grep mysql
naoya.ohsaki     66169   0.0  0.0  4295688    848 s001  S+   11:12AM   0:00.01 grep mysql
naoya.ohsaki     65853   0.0  4.8  4879852 398528   ??  S    11:02AM   0:02.46 /usr/local/opt/mysql/bin/mysqld --basedir=/usr/local/opt/mysql --datadir=/usr/local/var/mysql --plugin-dir=/usr/local/opt/mysql/lib/plugin --log-error=GX1794.local.err --pid-file=GX1794.local.pid
naoya.ohsaki     65756   0.0  0.0  4287968   1240   ??  S    11:02AM   0:00.03 /bin/sh /usr/local/opt/mysql/bin/mysqld_safe --datadir=/usr/local/var/mysql
```