Re: Tramp: hangs with “found remote shell prompt”, got `run nil “/bin:/usr/bin”` repeatedly in debug buffer

[Michael Albinus]

Wenguang Wang <address@hidden> writes:

> Michael,

Hi,

> I hope the error message is not "found remote shell prompt” when it
> cannot find the shell prompt :)
>
> So I added the following line in the “~/.profile” of the Linux box:
>
> [[ $TERM == "dumb" ]] && PS1='$ ' && return

That looks good.

> This changed the shell prompt to “$ “. Then I ran the following
> command:
>
> (setq tramp-shell-prompt-pattern "^[^>$][>$] *")

This shouldn't be necessary. There's always a chance that some hidden
escape sequences are transferred. Tramp tries to handle them.

Btw, which shell do you run remotely? zsh?

> Now my tramp session hang on a slightly different error message: Found
> remote shell prompt on ‘homes.local’
>
> And the full trace file is below:
> 19:09:20.311865 tramp-send-command (6) # exec ssh -l local  -o 
> ControlMaster=auto -o ControlPath='tramp.%C' -o ControlPersist=no -e none 
> homes.local
> 19:09:21.224814 tramp-process-actions (6) # 
> Welcome to Ubuntu 18.04.4 LTS (GNU/Linux 4.15.0-76-generic x86_64)
>
>  * Documentation:  https://help.ubuntu.com
>  * Management:     https://landscape.canonical.com
>  * Support:        https://ubuntu.com/advantage
>
>  * Kubernetes 1.18 GA is now available! See https://microk8s.io for
> docs or
>    install it with:
>
>      sudo snap install microk8s --channel=1.18 --classic
>
>  * Multipass 1.1 adds proxy support for developers behind enterprise
>    firewalls. Rapid prototyping for cloud operations just got easier.
>
>      https://multipass.run/
>
>  * Canonical Livepatch is available for installation.
>    - Reduce system reboots and improve kernel security. Activate at:
>      https://ubuntu.com/livepatch
>
> 5 packages can be updated.
> 4 updates are security updates.
>
> *** System restart required ***
> Last login: Tue Apr  7 19:08:40 2020 from
> fe80::1c74:9720:e127:bea4%wlp2s0
> $ 
> 19:09:21.224922 tramp-get-connection-property (7) # process-buffer nil
> 19:09:21.225137 tramp-process-actions (3) # Waiting for prompts from
> remote shell...done
> 19:09:21.225319 tramp-maybe-open-connection (3) # Found remote shell
> prompt on ‘homes.local’

This is the message about "Found remote shell prompt". And this is true, indeed.

> 19:09:21.227484 tramp-send-command (6) # echo \"`getconf PATH 2>/dev/null`\" 
> 2>/dev/null; echo tramp_exit_status $?
> 19:09:24.258471 tramp-accept-process-output (10) # *tramp/ssh 
> local@homes.local* run nil
> "/bin:/usr/bin"
> tramp_exit_status 0
> $ 

And here Tramp hangs. Hmm, it shouldn't.

Could you pls repeat the test, w/o changing tramp-shell-prompt-pattern?
Best would be to run

emacs -Q --eval '(tramp-verbose 10)'

and then open the remote file.

Best regards, Michael.