armbian-next: still fighting tee leaking under duress, and I think I won

- call `check_and_close_fd_13()` directly when `exit_with_error()` called, don't wait for trap
- store PID spawned by `do_with_logging()` under `$global_tee_pid`
- `check_and_close_fd_13()`:
  - sprinkle with `sync` to give a chance for stuff to die gracefully
  - check if `$global_tee_pid` is set and actually a running PID, if so, kill it
  - do not blindly "wait" for stuff, instead, kill it and wait for it to die -- 100% more likely to not hang ;-)

lib/functions/logging/logging.sh

@@ -102,14 +102,24 @@ function print_current_asset_log_base_file() {
 
 function check_and_close_fd_13() {
 	if [[ -e /proc/self/fd/13 ]]; then
-		display_alert "Closing fd 13" "log still open" "cleanup"
-		exec 13>&- || true # close the file descriptor, lest sed keeps running forever.
-		display_alert "Waiting for tee to finish" "if it's still running" "cleanup"
-		wait || true # wait for the tee process to finish
-		display_alert "Done waiting for tee/fd13" "it's gone" "cleanup"
+		sync                                                     # let the disk catch up
+		display_alert "Closing fd 13" "log still open" "cleanup" # no reason to be alarmed
+		exec 13>&- || true                                       # close the file descriptor, lest sed keeps running forever.
+		sync                                                     # make sure the file is written to disk
+		sleep 1                                                  # give it a second to die.
 	else
-		display_alert "fd 13 is not open" "nothing to do" "cleanup"
+		display_alert "Not closing fd 13" "log already closed" "cleanup"
 	fi
+
+	display_alert "Checking if global_tee_pid is set and running" "global_tee_pid: ${global_tee_pid}" "cleanup"
+	if [[ -n "${global_tee_pid}" && ${global_tee_pid} -gt 1 ]] && ps -p "${global_tee_pid}" > /dev/null; then
+		display_alert "Killing global_tee_pid" "${global_tee_pid}" "cleanup"
+		kill "${global_tee_pid}" && wait "${global_tee_pid}"
+		sync # wait for the disk to catch up
+	else
+		display_alert "Not killing global_tee_pid" "${global_tee_pid} not running" "cleanup"
+	fi
+
 }
 
 function discard_logs_tmp_dir() {

lib/functions/logging/section-logging.sh

@@ -49,6 +49,9 @@ function do_with_logging() {
 		prefix_sed_contents="$(logging_echo_prefix_for_pv "tool")   $(echo -n -e "${tool_color}")" # spaces are significant
 		local prefix_sed_cmd="s/^/${prefix_sed_contents}/;"
 
+		# global var to store the pid of spawned logging process.
+		declare -g -i global_tee_pid=0
+
 		# Create a 13rd file descriptor sending it to sed. https://unix.stackexchange.com/questions/174849/redirecting-stdout-to-terminal-and-file-without-using-a-pipe
 		# Also terrible: don't hold a reference to cwd by changing to SRC always
 		# There's handling of this fd 13 in check_and_close_fd_13()
@@ -57,6 +60,9 @@ function do_with_logging() {
 			# First, log to file, then add prefix via sed for what goes to screen.
 			tee -a "${CURRENT_LOGFILE}" | sed -u -e "${prefix_sed_cmd}"
 		)
+		# get the pid of the spawned process, so we can kill it later.
+		global_tee_pid=$!
+
 		"$@" >&13
 		exec 13>&- # close the file descriptor, lest sed keeps running forever.
 	else

lib/functions/logging/traps.sh

@@ -163,6 +163,9 @@ function exit_with_error() {
 	#exec {FD}> /var/lock/armbian-debootstrap-losetup
 	#flock -u "${FD}"
 
+	# let's try early to close tee/sed and fd 13 which might be opened if this happened in a logging section
+	check_and_close_fd_13
+
 	exit 43
 }