title: MongoDB can't find data directory after upgrading to Mac OS 10.15 (Catalina)
body: <p>I updated to MacOS 10.15 (Catalina) today. When I run <code>mongod</code> in the terminal it cannot find the <code>/data/db</code> directory:</p>
  
  <pre><code>➜  /Users/william &gt; mongod
  2019-10-08T17:02:44.183+0800 I CONTROL  [main] Automatically disabling TLS 1.0, to force-enable TLS 1.0 specify --sslDisabledProtocols 'none'
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten] MongoDB starting : pid=43162 port=27017 dbpath=/data/db 64-bit host=Williams-MacBook-Pro-6.local
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten] db version v4.0.3
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten] git version: 7ea530946fa7880364d88c8d8b6026bbc9ffa48c
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten] allocator: system
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten] modules: none
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten] build environment:
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten]     distarch: x86_64
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten]     target_arch: x86_64
  2019-10-08T17:02:44.209+0800 I CONTROL  [initandlisten] options: {}
  2019-10-08T17:02:44.211+0800 I STORAGE  [initandlisten] exception in initAndListen: NonExistentPath: Data directory /data/db not found., terminating
  2019-10-08T17:02:44.211+0800 I NETWORK  [initandlisten] shutdown: going to close listening sockets...
  2019-10-08T17:02:44.211+0800 I NETWORK  [initandlisten] removing socket file: /tmp/mongodb-27017.sock
  2019-10-08T17:02:44.211+0800 I CONTROL  [initandlisten] now exiting
  2019-10-08T17:02:44.211+0800 I CONTROL  [initandlisten] shutting down with code:100
  ➜  /Users/william &gt; 
  </code></pre>
  
  <p>I tried to install MongoDB with <code>brew</code>:</p>
  
  <pre><code>brew install mongodb
  
  ➜  /Users/william &gt; brew install mongodb
  Updating Homebrew...
  Error: mongodb: unknown version :mountain_lion
  </code></pre>
  
  <p>Any help?</p>