i3, screen-lock: the session's output to the journal, and the colour locker removed before i3lock is checked

lemurs leaves the session a stdout nobody reads, so a program writing to it dies of EPIPE.
i3lock-color provides i3lock, so with it still installed the host saw i3lock as present,
skipped the install and then removed the only locker; removing it first lets the same
apply install i3lock.

modules/i3/README.md

@@ -19,7 +19,7 @@ The window manager as a module (novox/hq ADR 0208, research 026, to-be 42 phase
 | `~/.config/i3/` | owned directory | its contents other than `config` are found and kept |
 | `~/.config/i3/config.d/` | owned directory | other modules' drop-ins, and yours |
 | `~/.config/i3/config` | owned (the found file kept once) | the main configuration, from [`config/config`](config/config) |
-| `/etc/lemurs/wms/i3` | owned | the login manager's session entry: `exec /bin/sh "$HOME/.xinitrc"` |
+| `/etc/lemurs/wms/i3` | owned | the login manager's session entry: `exec systemd-cat -t x-session /bin/sh "$HOME/.xinitrc"`, the session's output in the journal (`journalctl -t x-session`) because the login manager's pipe has no reader |
 
 **Drop-ins.** Another module adds to i3 with its own `~/.config/i3/config.d/<NN>-<module>.conf`. The
 `include` is the last line of the main file, so every variable set there (`$mod`, `$ws1`…`$ws10`) is

modules/i3/cmd/i3-tools/manifest_test.go

@@ -151,7 +151,7 @@ func TestTheLoginManagersEntryRunsTheSessionsStart(t *testing.T) {
 	if r["path"] != "/etc/lemurs/wms/i3" || r["mode"] != "0755" {
 		t.Fatalf("%v", r)
 	}
-	if !strings.Contains(r["content"].(string), `exec /bin/sh "$HOME/.xinitrc"`) {
+	if !strings.Contains(r["content"].(string), `exec systemd-cat -t x-session /bin/sh "$HOME/.xinitrc"`) {
 		t.Fatal("the entry runs the session's start, never i3 bare")
 	}
 	pkgs := map[string]bool{}

modules/i3/module.json

@@ -81,7 +81,7 @@
       "type": "file",
       "path": "/etc/lemurs/wms/i3",
       "mode": "0755",
-      "content": "#!/bin/sh\n# The i3 session (module i3, novox/hq ADR 0208), offered by the login manager. It runs the session's\n# start, ~/.xinitrc, which the display server's module writes and which ends by starting i3.\n# Replaced at every push.\nexec /bin/sh \"$HOME/.xinitrc\"\n"
+      "content": "#!/bin/sh\n# The i3 session (module i3, novox/hq ADR 0208), offered by the login manager. It runs the session's\n# start, ~/.xinitrc, which the display server's module writes and which ends by starting i3.\n# Replaced at every push.\n#\n# The login manager hands the session a stdout and stderr whose reading end nobody holds, so a\n# program that writes to them dies of EPIPE (an Electron tray app shows it as an error dialog).\n# The session's output goes to the journal instead, under `journalctl -t x-session`.\nexec systemd-cat -t x-session /bin/sh \"$HOME/.xinitrc\"\n"
     }
   ],
   "build": {

modules/screen-lock/module.json

@@ -29,16 +29,6 @@
     }
   ],
   "resources": [
-    {
-      "id": "watcher",
-      "type": "package",
-      "package": "xss-lock"
-    },
-    {
-      "id": "locker",
-      "type": "package",
-      "package": "i3lock"
-    },
     {
       "id": "colour-locker",
       "type": "package",
@@ -51,6 +41,16 @@
       "package": "xscreensaver",
       "absent": true
     },
+    {
+      "id": "watcher",
+      "type": "package",
+      "package": "xss-lock"
+    },
+    {
+      "id": "locker",
+      "type": "package",
+      "package": "i3lock"
+    },
     {
       "id": "wrapper",
       "type": "file",