`useGrpcForSearch` is only allowed on Linux machines with TLS. However, when attempting to start the server with this option on a non-Linux machine, this `MONGO_UNREACHABLE` macro is hit before the intended log line. As such, the reasoning why the server was unable to be started is unclear.

To fix this, we should add a log line before `MONGO_UNREACHABLE` is thrown to indicate to the user why their server didn't start up successfully.

This issue was found in this slack thread and can be reproduced locally on macOS ARM by running:

sudo path/to/mongod --dbpath=/Users/{USER}/data/db --setParameter useGrpcForSearch=true