When you’re trying to launch MongoDB deamon for the first time, you need to create
/data/db and give it
write permissions, Because otherwise you will be hit in the face with this error:
NonExistentPath: Data directory /data/db not found.
By default MongoDB deamon expects you to have that directory in
/ but it’s impossible to do in MacOS Catalina, due to internal changes in the OS, which made root path read-only.
To overcome that obstacle you can for example create
/data/db in your user directory.
To do that, just run this command:
$ mkdir -p ~/data/db && mongod --dbpath ~/data/db
Issue found by @drakeooonnnn