I recently installed mongodb-2.6.0 with Homebrew.
After successfully installed, I tried to connect using the mongo command. I am receiving the following errors
I had the same issue and in looking in the log file I saw this:
{2019-03-09T11:57:32.136-0500 I STORAGE [initandlisten]
exception in initAndListen: NonExistentPath:
Data directory /usr/local/var/mongodb not found., terminating}
so I created the directory /usr/local/var/mongodb
issued the brew services restart mongodb command I was able to open the mongo console.