hq/01-RESEARCH/026-the-graphical-session-as-modules/01-what-the-workstations-run.md

01 — What the workstations run

Measured 2026-10-04 on the two workstations of one installation, read-only: a laptop with a hybrid GPU and an internal panel, and a desktop with one GPU and two external monitors. Both run the same predecessor-generated desktop. File equality was checked by checksum across the two machines.

How a session starts

The chain is the same on both:

1. The login manager (lemurs, built from the distribution's user repository, its package now in the official one) runs its X setup script on a virtual terminal.
2. That script sources the login shell's profile files, then ~/.xprofile, then the system's xinitrc.d drop-ins, then merges ~/.Xresources.
3. ~/.xprofile reuses the systemd user manager's bus, then sources ~/.xinitrc.
4. ~/.xinitrc sets up the session and ends with exec i3.

The login manager's own window-manager entry (exec startx) is never reached. Its configuration file uses a format two releases old, and an unmerged newer one sits beside it.

What ~/.xinitrc does, in order:

1. Sources the system drop-ins, which import DISPLAY and XAUTHORITY into the user manager.
2. Starts the keyring and exports its ssh socket.
3. Exports the session's environment:
   • PATH, with nine entries, one of them a directory that no longer exists;
   • toolchain variables;
   • XDG_CONFIG_HOME and XDG_DATA_DIRS (with flatpak);
   • five GTK/Qt theme variables;
   • the desktop's identity (XDG_CURRENT_DESKTOP, XDG_SESSION_DESKTOP);
   • three of the operator's own variables.
4. Imports an explicit allowlist of ten of those into the user manager and D-Bus activation. It is never --all, because:
5. a predecessor file of secrets as environment variables (package-registry and API tokens) is sourced next.
6. Sets the screensaver and display power timeouts, restores the wallpaper, and starts the lock watcher in a respawn loop. It is deliberately not a unit, because it needs the login session.
7. exec i3.

The account's environment, as of today, has three sources that disagree:

• this file, for the session;
• the mesh's environment.sh, for shells (ADR 0203);
• ~/.config/environment.d/, for the user manager. It holds the mesh's 50-mesh.conf, and a predecessor file that sets PATH outright and sorts after it.

The roles, and what fills them

role	software	where configured
login manager	lemurs	/etc/lemurs/* (identical on both, and to the predecessor's source)
session start and environment	the login manager's X setup, ~/.xprofile, ~/.xinitrc, xinitrc.d, the D-Bus import, environment.d	~/.xprofile, ~/.xinitrc, ~/.config/environment.d/*
display server	Xorg (xorg-server, xinit, the X apps; vendor drivers per GPU)	no xorg.conf.d; monitors by xrandr scripts
monitor layout	xrandr scripts (arandr), a hotplug rule on the laptop	~/.screenlayout/, a scripts folder, a window-manager fragment
window manager	i3 4.25	~/.config/i3/config and config.d/*, a reload watcher (user unit)
bar	i3bar with i3status-rust	~/.config/i3status-rust/*, 14 themes, a bar watchdog (user unit)
terminal	xterm (the only terminal installed)	~/.Xresources.d/xterm, the window manager's binding, the compositor's opacity rule
compositor	picom	~/.config/picom/picom.conf
launcher and menus	rofi	~/.config/rofi/*, launcher, power-menu and theme-picker scripts
notifier	dunst (D-Bus activated)	~/.config/dunst/dunstrc, dunstrc.d/*
lock, idle, display power	xss-lock and i3lock-color, xset	~/.xinitrc, a lock script
clipboard	greenclip, xclip	greenclip.toml
wallpaper	feh	~/.fehbg (points into the predecessor's tree)
theming	Adwaita dark, qt5ct/qt6ct, the desktop portal (GTK backend pinned)	GTK settings.ini, qt*ct.conf, portals.conf, an appearance script, .Xresources cursor
fonts	Hack and Meslo Nerd fonts in ~/.local/share/fonts (not packaged), noto	~/.Xresources.d/xft (DPI fixed at 96)
keyboard	nothing set; the default layout; vendor keys via triggerhappy on the laptop	window-manager bindings, /etc/triggerhappy

Packages: every piece except two is in the distribution's official repositories, and the login manager now is too. The two exceptions are the lock screen's colour build (i3lock-color) and the clipboard manager (rofi-greenclip). The Nerd fonts exist as official packages, but both machines carry hand-copied files instead.

Identical, different, and why

Byte-identical on both machines:

• the session files: .xinitrc, .xprofile, .Xresources and its drop-ins;
• the i3 main configuration and two of its fragments;
• the bar's top configuration and themes;
• picom, rofi, the GTK and Qt settings, the portal configuration, the login manager.

Different, by cause:

cause	what
hardware	the monitor layout script; the bar's battery block; the laptop's power and vendor-key units and udev rules
misassignment	the desktop carries the laptop's hardware fragments: the vendor-key daemon and its triggers, the backlight rule, the brightness drop-in, a touchpad reset, and the laptop's monitor layouts, in an older version
drift	the notifier's position and corner radius; a "temporary" window-manager fragment from a test; the bar watchdog disabled; a second Qt configuration tool; different font builds
a stale session	the desktop's session began before two fixes, so it runs two notification daemons and two portals, and its user manager lacks the desktop's identity

Dead references: the window manager starts a polkit agent that is installed on neither machine, so there is no polkit agent at all. PATH names a directory that does not exist.

Per-machine values inside shared files:

• the DPI;
• absolute home paths, in the clipboard configuration and the flatpak data directories;
• the laptop's panel name, inside a fragment both machines carry.

User units the desktop needs

unit	does	laptop	desktop
reload watcher	reloads the window manager and bar when their files change	on	on
bar watchdog	restarts a dead bar	on	off
clipboard daemon	from its package	via the window manager	unit and window manager
vendor power profile, memory guard	laptop power	on	—

None is managed. Applying them as the account needs the host's user scope (ADR 0177), which is still an open change.

The predecessor's module

One manifest of 983 lines covers the window manager, bar, launcher, notifier, compositor, lock screen, session bootstrap, theming and scripts. It:

• has four flavors: i3, laptop (i3 plus the monitor wizard and hotplug), desktop (i3 plus nothing) and a laptop model (laptop plus vendor keys);
• has about 105 theme variables substituted into templates: border, gaps, fonts, workspace names, every colour of bar, launcher, notifier and lock screen, compositor opacity, cursor, idle times, Qt and GTK theme names;
• enables the two user units from an install hook.

Separate modules held the login manager and the display server (one flavor, xorg, with a comment calling wayland "the intended sibling"). The shell module held no graphical part.

Wayland and sway

Nothing exists. There is no compositor, no sway configuration, no Wayland session entry, and the login manager's Wayland directory is empty. What is installed is libraries:

• Wayland itself and the Qt Wayland plugins, which other packages pull in;
• xwayland, explicitly installed and required by nothing;
• on the desktop, an orphaned compositor library from another desktop environment, and that environment's portal backend, pulled in by a game launcher. The portal configuration pins against it.

Every piece a sway session needs is in the official repositories: the compositor, its lock screen, a terminal (foot), a bar (waybar), a notifier (mako) and xwayland.