Linux desktop support

[exbald]

Ships OpenWorker on Linux as a .deb and an .AppImage, with ChromeOS Crostini as the specific target (a Debian 12 container with no status area).

The Python server was already portable — every sys.platform branch had a working POSIX path. The desktop shell was the gap: it had never been built for Linux, and three of its behaviours would have kept the packaged app from working at all.

Screenshots

The contributing guide asks for before/after. There is no "before" to photograph here — before this PR there was no Linux build to run at all. So these are the "after": OpenWorker built from this branch, installed via apt, running on an arm64 Chromebook under Crostini. (The ChromeOS shelf is visible along the bottom of each.)

Running as a native app from the ChromeOS launcher.

A scheduled automation that fired, searched the web, and wrote its artifact — the scheduler, web search, and artifact pipeline all working on Linux.

Connectors live — the backend is the same Python server as on macOS/Windows.

What was actually broken

The app refused to start without a system tray. TrayIconBuilder::build(app)? propagated its error out of setup, so a session with no StatusNotifier host — Crostini has none — aborted launch over a tray icon. Now it logs and continues, and close-to-tray is gated on a tray existing; without one, closing the window quits instead of hiding it behind nothing.

A packaged install could never find its sidecar. A .deb puts the binary in /usr/bin and its resources in /usr/lib/OpenWorker/. Every candidate in server_bin() was relative to the executable's own directory, so resolution fell all the way through to the dev-venv path and the server never came up. Resolution now starts from Tauri's own resource_dir, which is right by construction on every platform.

ocw-stt doesn't belong in a Linux build. It compiles whisper.cpp (cmake + a C++ toolchain) and links ALSA — build-time cost on every checkout for a feature the Linux artifacts don't offer. It's now scoped to non-Linux targets and replaced by a dictation_stub module with the same API, so there is still exactly one set of Tauri commands. Voice Input reports unsupported, as it already did on Linux.

Rest of the shell

• Keep-awake holds a logind inhibitor (systemd-inhibit … cat), released by closing the pipe rather than killing the process — killing systemd-inhibit orphans its child, and closing the pipe also releases the lock if the app is hard-killed. It waits to confirm the inhibitor actually survives: systemd-inhibit exits immediately where it can't reach logind, and a successful spawn() alone would mean reporting a hold nobody is holding.
• Self-update is AppImage-only. Tauri rewrites $APPIMAGE; a .deb has no such file and its paths belong to dpkg. A new can_self_update command lets Settings say "this install updates through your package manager" rather than answering "you're on the latest version" without having checked.
• Crostini blank-window fix. WebKitGTK's DMABuf renderer draws nothing through virtio-gpu/Sommelier — the app looks hung with nothing in the log. The shell detects Crostini (ChromeOS-only markers) and disables that renderer unless the user set the variable themselves.
• PATH repair learned the Linux install dirs (~/.local/bin, ~/.cargo/bin, ~/go/bin, /snap/bin, Linuxbrew) and the login-shell probe falls back to bash where /bin/zsh doesn't exist.

Packaging, CI, backend

• packaging/build_linux.sh mirrors build_dmg.sh — freeze the sidecar, stage it, bundle. Checks the system libraries up front so a missing one fails with the apt line, not a pkg-config error 400 lines into a cargo build.
• packaging/bootstrap_linux.sh takes a bare machine to a runnable checkout in one command: system libraries, Rust, Node 20 (Debian 12 ships 18), the venv, npm deps — skipping whatever is already present, and asking before it touches anything.
• tauri.conf.json: Linux bundle config plus real package descriptions (the .deb shipped Description: … / (none)).
• release.yml builds linux-x64 and linux-arm64 on ubuntu-22.04, not the newest image: glibc is forward- but not backward-compatible, and a 24.04 build (glibc 2.39) will not start on Debian 12 (glibc 2.36) — which is what Crostini runs. latest.json gains the AppImage platform keys; the .deb is deliberately absent from it.
• New ci.yml job compiles and tests the shell on Linux. Nothing did before, so a Linux break would first have surfaced at release time.
• The server-side folder picker tries zenity → kdialog → qarma instead of assuming zenity, and stops at the first one installed.
• docs/linux.md: install, Crostini setup, the platform-difference table, build-from-source, troubleshooting.

Verification

On real hardware — the arm64 Chromebook in the screenshots above:

• bootstrap_linux.sh on a bare machine: 281 apt packages, fresh rustup install, existing Node detected and skipped — exit 0.
• build_linux.sh → OpenWorker_0.2.1_arm64.deb (85 MB); Rust compile 7m20s.
• apt install registered the desktop entry and 32/128/256@2 icons; the app launches from the ChromeOS launcher.
• The shell spawned the frozen sidecar from /usr/lib/OpenWorker/sidecar/openworker-server. Unauthenticated requests to its port get HTTP 401 — the shell holds the launch token, so the server correctly refuses everyone else.

On x86_64 Ubuntu (headless): .deb (71 MB) + .AppImage (136 MB); installed the .deb and launched under Xvfb — sidecar found and started, SPA served live traffic (/v1/sessions, /v1/inbox, /v1/workspaces/recent, /v1/automations all 200), no orphaned server after exit.

Test suites: pytest tests 1847 passed; GUI typecheck + 134 unit tests green; cargo test --lib green (4 new tests covering sidecar resolution, the Linux voice-support flag, and the keep-awake invariant). All four CI jobs green, including the new desktop-shell-linux.

Not included

Voice Input on Linux — the one deliberate gap, documented in docs/linux.md; enabling it later is a one-line change to the ocw-stt dependency guard plus two apt packages. Linux artifacts are also unsigned; the platform has no notarization equivalent, and only the AppImage updater tarball is minisigned.