fix(linux): make the Linux build actually work; add CI

.github/workflows/ci.yml

@@ -0,0 +1,65 @@
+name: CI
+
+# Build and test on every push / PR. `release.yml` only ever fires on a tag, so
+# without this nothing compiles the Linux target until release time — and the
+# Linux-gated code (audio/pulse.rs, the non-Windows half of keys.rs,
+# autostart.rs) is invisible to a Windows developer's compiler entirely.
+on:
+  push:
+    branches-ignore:
+      - "gh-pages"
+  pull_request:
+  workflow_dispatch:
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  linux:
+    name: Linux (build + test)
+    runs-on: ubuntu-24.04
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y --no-install-recommends \
+            pkg-config libudev-dev libxkbcommon-dev libxkbcommon-x11-dev \
+            libwayland-dev libxcb1-dev libfontconfig1-dev
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+
+      - name: Cache cargo
+        uses: Swatinem/rust-cache@v2
+        with:
+          key: ci-linux
+          cache-all-crates: true
+
+      # Type-checks the Linux-only modules that never see a compiler on a
+      # Windows dev machine.
+      - name: cargo check
+        run: cargo check --all-targets
+
+      - name: cargo test
+        run: cargo test
+
+      - name: cargo build --release
+        run: cargo build --release
+
+      # The shipped Linux binary is a bare dynamically-linked ELF, so anything
+      # in DT_NEEDED must exist on a plain desktop. Print it so a newly
+      # introduced native dependency (libxdo, libpulse, ...) is visible in the
+      # log instead of surfacing as "it won't start" on a user's machine.
+      - name: Report runtime library dependencies
+        run: |
+          ldd target/release/slidr || true
+          echo "--- DT_NEEDED ---"
+          readelf -d target/release/slidr | grep NEEDED || true

.github/workflows/release.yml

@@ -59,8 +59,8 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y --no-install-recommends \
-            pkg-config libpulse-dev libudev-dev libxkbcommon-dev libxkbcommon-x11-dev \
-            libwayland-dev libxcb1-dev libfontconfig1-dev libxdo-dev
+            pkg-config libudev-dev libxkbcommon-dev libxkbcommon-x11-dev \
+            libwayland-dev libxcb1-dev libfontconfig1-dev
 
       - name: Install dependencies (Windows build)
         if: matrix.target == 'windows'

Cargo.toml

@@ -49,19 +49,21 @@ slint = { version = "1.16", default-features = false, features = ["std", "compat
 # Build timestamp injected at compile time
 chrono = { version = "0.4", default-features = false, features = ["clock"] }
 
-# Key simulation (cross-platform)
-enigo = "0.2"
+# Key simulation (cross-platform).
+# Linux: the `x11rb` backend (pure Rust XTEST) instead of the default `xdo`
+# one. `xdo` is `#[link(name = "xdo")]`, which makes libxdo.so.3 a hard
+# load-time dependency of the shipped binary - it would refuse to start on any
+# machine without xdotool installed. `x11rb` has the same reach (X11 +
+# XWayland) with no native library. Native Wayland clients are unreachable
+# either way; `keys.rs` warns about that at startup.
+enigo = { version = "0.2", default-features = false, features = ["x11rb"] }
 
 # Cross-platform "open file/url"
 open = "5"
 
 # Native file dialog for "Browse…" buttons
 rfd = "0.15"
 
-[target.'cfg(target_os = "linux")'.dependencies]
-libpulse-binding = "2.28"
-udev = "0.8"
-
 [target.'cfg(target_os = "windows")'.dependencies]
 # Direct dep so the `#[interface]` macro's `::windows_core` paths resolve; pinned
 # to the same version `windows` re-exports as `windows::core` (shared types).

README.md

@@ -69,13 +69,42 @@ installer/slidr.nsi   Interactive NSIS installer
 
 ```sh
 # Linux dev deps (Ubuntu 24.04 names):
-sudo apt install build-essential pkg-config libpulse-dev libudev-dev \
+sudo apt install build-essential pkg-config libudev-dev \
     libxkbcommon-dev libxkbcommon-x11-dev libwayland-dev libxcb1-dev \
-    libxdo-dev libfontconfig1-dev
+    libfontconfig1-dev
 
 cargo run --release
 ```
 
+### Linux runtime requirements
+
+* **`pactl`** (Ubuntu/Debian/Fedora: `pulseaudio-utils`). The audio backend
+  shells out to it; it also ships with `pipewire-pulse`. Without it Slidr
+  starts but every volume/mute action is a no-op.
+* **Serial port access.** Opening `/dev/ttyUSB*` / `/dev/ttyACM*` needs
+  permission, or the connection banner shows "Access denied". Either install
+  the bundled udev rule (preferred - applies on replug, no group, no re-login):
+
+  ```sh
+  sudo install -m644 packaging/99-slidr.rules /etc/udev/rules.d/99-slidr.rules
+  sudo udevadm control --reload-rules && sudo udevadm trigger
+  ```
+
+  or add yourself to the port's group and log out and back in:
+
+  ```sh
+  sudo usermod -aG dialout "$USER"
+  ```
+* **Key actions need an X11 session.** Simulated keypresses go out over XTEST,
+  which reaches X11 and XWayland windows but *not* native Wayland windows - a
+  Wayland compositor does not let an ordinary application inject input. On a
+  Wayland session Slidr logs a warning at startup and key actions will appear
+  to do nothing in Wayland-native apps; volume, mute, LED and API actions are
+  unaffected. Pick the "Xorg"/"X11" session at login if you need key actions.
+* **No system tray.** The tray (`src/tray.rs`) is Windows-only, so the
+  tray-related settings are hidden on Linux and `--hidden` is ignored - it
+  would otherwise leave a window-less process that cannot be reopened.
+
 Override the config location with `SLIDR_CONFIG_DIR=/path` (default
 `$XDG_CONFIG_HOME/slidr`, i.e. `~/.config/slidr`; `%APPDATA%/slidr` on Windows).
 

deploy.sh

@@ -40,7 +40,8 @@ fi
 # ── Publish ──────────────────────────────────────────────────────────────
 log "Publishing to $WEBROOT"
 mkdir -p "$WEBROOT"
-install -m644 target/release/slidr            "$WEBROOT/Slidr-linux-x86_64"
+# 0755: this is a binary users download and run, not a document.
+install -m755 target/release/slidr            "$WEBROOT/Slidr-linux-x86_64"
 if [[ "$SKIP_WINDOWS" -eq 0 ]]; then
   install -m644 installer/Slidr-windows-setup.exe       "$WEBROOT/Slidr-windows-setup.exe"
   install -m644 "target/$WIN_TARGET/release/slidr.exe"  "$WEBROOT/Slidr-windows-portable.exe"

packaging/99-slidr.rules

@@ -0,0 +1,28 @@
+# udev rules for Slidr — grant the logged-in desktop user access to the board's
+# serial port without adding them to a group or running the app as root.
+#
+# Install:
+#   sudo install -m644 packaging/99-slidr.rules /etc/udev/rules.d/99-slidr.rules
+#   sudo udevadm control --reload-rules && sudo udevadm trigger
+#
+# Without this (or membership in the port's owning group, usually `dialout`),
+# opening /dev/ttyUSB* / /dev/ttyACM* fails with "Permission denied (os error 13)"
+# and Slidr reports "Access denied" on the connection banner.
+#
+# The VID list mirrors KNOWN_USB_VIDS in src/serial.rs — keep the two in sync.
+
+# Arduino LLC (Uno, Mega, Nano 33, ...)
+SUBSYSTEM=="tty", ATTRS{idVendor}=="2341", TAG+="uaccess"
+# Atmel / Arduino Leonardo, Micro, Pro Micro
+SUBSYSTEM=="tty", ATTRS{idVendor}=="0d28", TAG+="uaccess"
+# WCH CH340 / CH341 (most Nano clones)
+SUBSYSTEM=="tty", ATTRS{idVendor}=="1a86", TAG+="uaccess"
+# FTDI FT232
+SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", TAG+="uaccess"
+# Silicon Labs CP210x
+SUBSYSTEM=="tty", ATTRS{idVendor}=="10c4", TAG+="uaccess"
+
+# `uaccess` hands the device to whoever is logged in at the seat, which is what
+# you want on a single-user desktop. On systems without systemd-logind, replace
+# the TAG with a group instead, e.g.:
+#   SUBSYSTEM=="tty", ATTRS{idVendor}=="2341", MODE="0660", GROUP="dialout"

src/audio/mod.rs

@@ -6,6 +6,9 @@
 
 #[cfg(target_os = "linux")]
 pub mod pulse;
+// Pure `pactl` output parsers. Compiled everywhere (not gated) so they stay
+// unit-testable on any host; only `pulse` consumes them.
+pub mod pulse_parse;
 #[cfg(target_os = "windows")]
 pub mod wasapi;
 pub mod null;