Reach the real user service manager from Desktop Mode's nested session

Konsole on the Frame runs with XDG_RUNTIME_DIR=/run/user/1000/nested_plasma
and a private D-Bus, so systemctl --user failed in the installer.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -29,7 +29,15 @@ On the headset, switch to Desktop Mode, open **Konsole** and paste:
 curl -fsSL https://github.com/bod09/frame-autopass/releases/latest/download/install.sh | bash
 ```
 
+Or the short version, easier to type in VR:
+
+```sh
+curl -L bod09.github.io/frame-autopass/i | bash
+```
+
 That's it. It starts automatically whenever SteamVR runs, from now on.
+Tip: the code blocks on GitHub have a copy button; paste into Konsole with
+Ctrl+Shift+V.
 
 The installer checks that the Arcturus module is present, downloads the
 latest release, verifies its checksum, puts two programs in

install.sh

@@ -21,6 +21,12 @@ fail() { printf 'frame-autopass: %s\n' "$*" >&2; exit 1; }
 [ "$(uname -m)" = "aarch64" ] || fail "this is for the Steam Frame (aarch64); this machine is $(uname -m)."
 command -v systemctl >/dev/null || fail "systemd not found."
 
+# Desktop Mode on the Frame runs Konsole in a nested session with its own
+# XDG_RUNTIME_DIR and D-Bus, where `systemctl --user` cannot reach the real
+# user service manager. Always talk to the login session's one.
+export XDG_RUNTIME_DIR="/run/user/$(id -u)"
+export DBUS_SESSION_BUS_ADDRESS="unix:path=$XDG_RUNTIME_DIR/bus"
+
 if ! grep -qs arcimx616 /sys/class/video4linux/*/name; then
     fail "the Arcturus Vision colour module was not found. frame-autopass switches between that module
 and the built-in IR cameras, so it needs the module attached."

tools/autopass.cpp

@@ -54,9 +54,12 @@ std::string unit_path() {
     return base + "/systemd/user/" + kUnit;
 }
 
-// Runs `systemctl --user ARGS...`, returns its exit code.
+// Runs `systemctl --user ARGS...`, returns its exit code. Always against
+// the login session's user manager: Desktop Mode on the Frame runs Konsole
+// in a nested session whose XDG_RUNTIME_DIR and D-Bus cannot reach it.
 int systemctl(std::initializer_list<const char*> args, bool quiet = false) {
-    std::string cmd = "systemctl --user";
+    const std::string run = "/run/user/" + std::to_string(::getuid());
+    std::string cmd = "XDG_RUNTIME_DIR=" + run + " DBUS_SESSION_BUS_ADDRESS=unix:path=" + run + "/bus systemctl --user";
     for (const char* a : args) cmd += std::string(" ") + a;
     if (quiet) cmd += " >/dev/null 2>&1";
     const int rc = std::system(cmd.c_str());
@@ -204,7 +207,8 @@ int report() {
     section(&out, "date", "date");
     section(&out, "SteamOS", "grep -E '^(VERSION_ID|BUILD_ID)=' /etc/os-release");
     section(&out, "SteamVR", "cat /opt/steamvr/bin/version.txt; grep -m1 -E 'cv: version [0-9]' ~/.local/share/Steam/logs/vrserver.txt");
-    section(&out, "unit", std::string("systemctl --user status --no-pager ") + kUnit + " | head -5");
+    section(&out, "unit", "XDG_RUNTIME_DIR=/run/user/" + std::to_string(::getuid()) +
+                              " systemctl --user status --no-pager " + kUnit + " | head -5");
     section(&out, "status", "cat " + autopass::status_path());
     section(&out, "config", "cat " + autopass::conf_path() + " 2>/dev/null || echo '(defaults)'");
     section(&out, "crash guard", "cat " + autopass::crash_guard_path() + " 2>/dev/null || echo '(empty)'");