Comment 2 for bug 1792508

Alright, it is not that black and white, so here're the reproduction steps:
Assumption: no byobu, tmux, nor screen processes are running
$ ps -ef |grep byobu
And if they do, kill them.

STEPS:
1. List all sessions:
$ byobu ls
no server running on /private/tmp/tmux-501/default

2. Start byobu. It surprisingly starts
$ byobu

3. List sessions again within the byobu session
$ byobu ls
1: 2 windows (created Sat Sep 29 23:00:15 2018) [153x20] (attached)

4. Detach from byobu (F6)
[detached (from session 1)]

5. List again its sessions
$ byobu ls
1: 2 windows (created Sat Sep 29 23:00:15 2018) [153x20]

6. Try to launch byobu again
$ byobu
/opt/local/bin/byobu-select-session: /opt/local/lib/byobu/include/select-session.py: /usr/bin/python3: bad interpreter: No such file or directory
/opt/local/bin/byobu-select-session: line 24: /opt/local/lib/byobu/include/select-session.py: Undefined error: 0

7. Check for its running processes
$ ps -ef | grep byobu
  501 49530 1 0 11:00pm ?? 0:02.41 tmux -u -2 -f /opt/local/share/byobu/profiles/tmuxrc new-session -n - /opt/local/bin/byobu-shell
  501 59119 44965 0 11:07pm ttys000 0:00.00 grep --color=auto --exclude-dir=.bzr --exclude-dir=CVS --exclude-dir=.git --exclude-dir=.hg --exclude-dir=.svn byobu

8. Kill the byobu process
$ kill -9 49530

# delphym @ KiwiBook in /usr/bin [23:07:55]
$ echo $?
0

9. Check the processes again:
$ ps -ef | grep byobu
  501 59173 44965 0 11:08pm ttys000 0:00.00 grep --color=auto --exclude-dir=.bzr --exclude-dir=CVS --exclude-dir=.git --exclude-dir=.hg --exclude-dir=.svn byobu

10. Repeat from step #1