Linux (x64) desktop packaging — working build and a minimal patch series

[JulianZBY]

Linux (x64) desktop packaging — working build and a minimal patch series

Proposed for GitHub Discussions. Base: master @ 22ddee37 (the dsh-v0.2.1-rc.3 line).
Branch: linux-desktop-packaging (4 commits, linked fork to be attached).

Context

The desktop packaging scripts in apps/desktop currently cover
mac-arm64, mac-x64 and win-x64 only, and the GitHub releases carry
no desktop artifacts for Linux. This series opens the linux-x64 target
with the smallest set of changes we could find, and ends with a working,
self-contained desktop build on Fedora 44 (Wayland).

What the series does

1. Add linux-x64 as a supported desktop packaging target — extends the
   target unions (DesktopAutoUpdateTarget, build-path declarations),
   maps linux-x64 to the linux platform in
   desktopTargetPlatform(), and selects the correct Electron
   executable layout when preparing the runtime and CLI.
2. Skip the sharp payload smoke check on Linux — prebuilt sharp
   binaries SIGSEGV under Electron on Linux (documented upstream at
   sharp.pixelplumbing.com/install#electron-and-linux). The remaining
   payload checks (koffi, pty, pnpm, grep, glob, html) and the office
   round-trips all pass on Linux.
3. Linux adjustments for the desktop shell — skip the
   mandatory-update policy where it is unsupported (system package
   manager owns updates there), point the HTTP cache at
   XDG_CACHE_HOME (leaf directory name kept identical to macOS and
   Windows), and suppress the application menu (no global menu bar host
   on typical Linux compositors, so it would render inside the window).
4. Dev-launch flags for Linux — the unpackaged Electron distribution
   has no setuid chrome-sandbox, and NVIDIA+Wayland currently
   crash-loops the GPU process, so scripts/dev.ts needs
   --no-sandbox --disable-gpu.

Verification

• pnpm run build --profile local gates: 10 passed, 0 failed.
• electron-builder --linux dir produces a working linux-unpacked
  app (app.asar 187 MB, unpacked dsh payload 215 MB, bundled runtime
  401 MB).
• Boot-tested on Fedora 44 / Hyprland (Wayland): window, login,
  sessions, embedded dsh web server all work.

Open questions for maintainers

• Is Linux desktop support interesting for this repo at all, or should
  it stay community-maintained?
• sharp: what is the preferred strategy — build from source for
  Electron, vendor a compatible prebuild, or gate image features off on
  Linux for now?
• Updates/policy: is "system package manager owns updates" an
  acceptable posture for officially packaged Linux builds?
• Menu: suppress entirely (current behavior), or keep a minimal menu?

Reproducing

pnpm install && pnpm build --profile local
cd apps/desktop
DSH_DESKTOP_TARGET_PLATFORM=linux \
DSH_DESKTOP_APP_ID=<reverse-dns-id> \
DSH_DESKTOP_UNSIGNED=1 \
DSH_DESKTOP_AUTO_UPDATE_ENV=production \
DSH_DESKTOP_MANDATORY_UPDATE_PROD_ORIGIN=https://example.invalid \
  node_modules/.bin/electron-builder --linux dir \
  --config electron-builder.config.mjs
# artifact: .desktop-build/targets/linux-x64/unsigned-artifacts/linux-unpacked

prepare-runtime / prepare-package-set / prepare-dsh run as usual
before packaging; the office document round-trips pass on Linux.