Can I re-attach to a detached mosh session?

Question

When I connect using mosh I get the following error:

Mosh: You have 2 detached Mosh sessions on this server, with PIDs:
    - mosh [3700]
    - mosh [31091]

How can I resume one of these sessions?

Answer 1

You can't. Once the client is dead, you can't re-attach to the server session.

https://github.com/keithw/mosh/issues/394

For security reasons, you can only resume a connection to a mosh-server from the corresponding mosh-client. If the client is dead (e.g. the user quit the client while it was off the network), the only option is to kill the server with that PID (e.g. kill 12726).