[cfarm-users] AppleMac M1 screen/nohup problems (was: Trouble with new Apple Mac M1)

[Assaf Gordon]

Hello all,

On 2021-03-23 4:09 p.m., Paul H. Hargrove via cfarm-users wrote:
> I can reproduce Pierre's issues with nohup and screen on the CFarm 
> machine, but not when ssh'ed into my own M1-based MacMini.
> I know that doesn't help at all finding a solution, but it is hopefully 
> reassuring to know it *can* work.

While I don't know the reason for the failure,
I can suggest an alternative:
The homebrew versions ( /opt/homebrew/bin/screen , 
/opt/homebrew/bin/gnohup ) do work as expected.

I found two old posts mentioning similar issues,
so it's likely not specific to the M1 or the latest OS:

NoHup:
https://github.com/ChrisJohnsen/tmux-MacOSX-pasteboard/blob/master/Usage.md#beyond-pasteboard-access


GNU Screen:
https://superuser.com/questions/207654/gnu-screen-freezes-when-starting-session-over-ssh-works-locally-whats-wrong
and a relevant answer on same page, mentioning the call to 
"vprocmgr_detach_from_console": https://superuser.com/a/208685


Indeed, the apple version call it (and the gnu/homebrew version does not):
===
% nm /usr/bin/nohup
/usr/bin/nohup (for architecture arm64e):
                  U ___error
                  U ___stderrp
0000000100000000 T __mh_execute_header
                  U __vprocmgr_detach_from_console
                  U _dup2
                  U _err
                  U _errx
                  U _execvp
                  U _exit
                  U _fprintf
                  U _fwrite
                  U _getenv
                  U _getopt
                  U _isatty
                  U _lseek
                  U _open
                  U _optind
                  U _signal
                  U _snprintf
===

It is a custom Apple addition:
https://opensource.apple.com/source/shell_cmds/shell_cmds-149/nohup/nohup.c.auto.html


Hope this helps.
  - assaf gordon

P.S.
There's always "tmux" :)