`number_tmux_processes_except_current_server` is often overzealous

[YodaEmbedding]

If any plugin or script calls tmux <command>, then number_tmux_processes_except_current_server incorrectly reports an overly large value. This causes several problems, including lack of auto-start.

---

Log:

$ pkill tmux
$ killall tmux

$ tmux

$ tail ~/debug.log
current_tmux_server_pid=2172701
all_tmux_processes:
tmux                        2172699              <---- !!! (No idea why this shows up, tbh.)
tmux                        2172701
tmux show-option -gqv statu 2172857              <---- !!! (Also problematic.)
number_tmux_processes_except_current_server=2

$ tmux kill-server

$ tail ~/debug.log
current_tmux_server_pid=2173444
all_tmux_processes:
tmux                        2173442
tmux                        2173444
number_tmux_processes_except_current_server=1

---

Relevant code is in tmux-continuum/scripts/helpers.sh:

get_tmux_option() {
	local option="$1"
	local default_value="$2"
	local option_value=$(tmux show-option -gqv "$option")
	if [ -z "$option_value" ]; then
		echo "$default_value"
	else
		echo "$option_value"
	fi
}

set_tmux_option() {
	local option="$1"
	local value="$2"
	tmux set-option -gq "$option" "$value"
}

# multiple tmux server detection helpers

current_tmux_server_pid() {
	echo "$TMUX" |
		cut -f2 -d","
}

all_tmux_processes() {
	# ignores `tmux source-file .tmux.conf` command used to reload tmux.conf
	local user_id=$(id -u)
	ps -u $user_id -o "command pid" |
		\grep "^tmux" |
		\grep -v "^tmux source"
}

number_tmux_processes_except_current_server() {
	all_tmux_processes |
		\grep -v " $(current_tmux_server_pid)$" |
		wc -l |
		sed "s/ //g"
}

number_current_server_client_processes() {
	tmux list-clients |
		wc -l |
		sed "s/ //g"
}

another_tmux_server_running_on_startup() {
	# there are 2 tmux processes (current tmux server + 1) on tmux startup
	[ "$(number_tmux_processes_except_current_server)" -gt 1 ]
}

---

Helpful code for debugging:

another_tmux_server_running_on_startup() {
	echo "current_tmux_server_pid=$(current_tmux_server_pid)" >> ~/debug.log
	echo "all_tmux_processes:" >> ~/debug.log
	all_tmux_processes >> ~/debug.log
	echo "number_tmux_processes_except_current_server=$(number_tmux_processes_except_current_server)" >> ~/debug.log

	# there are 2 tmux processes (current tmux server + 1) on tmux startup
	[ "$(number_tmux_processes_except_current_server)" -gt 1 ]
}

---

Possible fixes:

• Disable multi-tmux detection altogether. Very few users do this anyways.
• Remove interference from get_tmux_option via grep -v '^tmux \(show-option\|set-option\|et cetera\)'.
• Beg the tmux developers for a way to enumerate all tmux servers by user id.

---

Related:

• https://github.com/tmux-plugins/tmux-continuum/blob/master/docs/multiple_tmux_servers.md
• Autosave not working #48