mux: platform module + Linux CI (phase 1 of Windows/Linux support)

.github/workflows/mux.yml

@@ -22,14 +22,25 @@ permissions:
 
 jobs:
   test:
-    runs-on: ${{ vars.MACOS_RUNNER_15 || 'blacksmith-6vcpu-macos-15' }}
+    name: test (${{ matrix.os }})
+    runs-on: ${{ matrix.os == 'macos' && (vars.MACOS_RUNNER_15 || 'blacksmith-6vcpu-macos-15') || 'ubuntu-latest' }}
     timeout-minutes: 40
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos, linux]
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Init ghostty submodule
         run: git submodule update --init --depth 1 ghostty
 
+      - name: Install Linux build dependencies
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y clang libclang-dev pkg-config
+
       - name: Install zig
         run: ./scripts/install-zig-ci.sh
 
@@ -62,3 +73,36 @@ jobs:
       - name: Detach/reattach smoke test
         working-directory: mux
         run: python3 scripts/smoke-attach.py
+
+  windows-experimental:
+    name: windows experimental (x86_64-gnu)
+    runs-on: windows-latest
+    timeout-minutes: 40
+    continue-on-error: true
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Init ghostty submodule
+        run: git submodule update --init --depth 1 ghostty
+
+      - name: Install zig
+        uses: mlugg/setup-zig@8d6198c65fb0feaa111df26e6b467fea8345e46f # v2.0.5
+        with:
+          version: 0.15.2
+
+      - name: Install Rust GNU target
+        shell: bash
+        run: |
+          rustup target add x86_64-pc-windows-gnu
+          echo "C:\\msys64\\mingw64\\bin" >> "$GITHUB_PATH"
+
+      - name: Build libghostty-vt for Windows GNU
+        shell: bash
+        working-directory: ghostty
+        run: |
+          zig build -Demit-lib-vt=true -Demit-xcframework=false -Doptimize=ReleaseFast -Dtarget=x86_64-windows-gnu --prefix "$RUNNER_TEMP/ghostty-vt-win-gnu"
+          zig ar t "$RUNNER_TEMP/ghostty-vt-win-gnu/lib/ghostty-vt-static.lib" | head
+
+      - name: cargo build mux-tui for Windows GNU
+        working-directory: mux
+        run: cargo build -p mux-tui --target x86_64-pc-windows-gnu --locked

mux/Cargo.toml

@@ -28,6 +28,7 @@ unicode-width = "0.2"
 base64 = "0.22"
 libc = "0.2"
 tungstenite = { version = "0.24", default-features = false, features = ["handshake"] }
+uds_windows = "1.2"
 
 [profile.release]
 lto = "thin"

mux/README.md

@@ -24,6 +24,14 @@ cargo test                      # unit + integration tests
 
 Detach with prefix-d while attached; the headless session keeps running and `attach` reconnects with full screen state (VT replay + live stream). A local (non-attach) `cmux-mux` ends its session on quit.
 
+## Platforms
+
+cmux-mux supports macOS and Linux. Runtime sockets live under `$XDG_RUNTIME_DIR/cmux-mux-<uid>` when `XDG_RUNTIME_DIR` is set, then `$TMPDIR/cmux-mux-<uid>`, then `/tmp/cmux-mux-<uid>`. Config uses `CMUX_MUX_CONFIG`, then `$XDG_CONFIG_HOME/cmux/mux.json`, then `~/.config/cmux/mux.json`; Ghostty selection colors are seeded from `$XDG_CONFIG_HOME/ghostty/config`, `~/.config/ghostty/config`, and on macOS the Ghostty Application Support config. Launched Chrome profiles use the macOS Application Support path or `$XDG_DATA_HOME/cmux-mux/chrome-profile`, falling back to `~/.local/share/cmux-mux/chrome-profile`.
+
+PTY tabs use `$SHELL`; if it is unset, Unix falls back to `/bin/bash` when present and then `/bin/sh`. Chrome discovery checks configured `browser.chrome_binary` first. macOS then checks the standard Chrome, Chromium, Brave, and Edge app bundles before PATH names; Linux checks `google-chrome`, `google-chrome-stable`, `chromium`, and `chromium-browser` from PATH, then common `/usr/bin`, `/snap/bin`, and `/opt` locations.
+
+Windows support via ConPTY is planned for phase 2; the transport, config, and shell seams are already isolated, but Windows is not documented as supported yet.
+
 Keys (prefix Ctrl-b, tmux-style): `c` new screen, `n`/`p` next/previous screen, `&` close screen, `,` rename screen, `t` new PTY tab, `B` new browser tab URL prompt, `Tab`/`BackTab` next/previous tab, `1`-`9` select tab, `%` split right, `"` split down, `h j k l`/arrows move focus, `x` close tab, `X` close pane, `$` rename workspace, `w`/`W` switch/create workspace, `s` toggle the workspace sidebar, PageUp/PageDown scrollback, `d` quit, `Ctrl-b` twice sends a literal Ctrl-b. Modeless Alt shortcuts are also on by default: `Alt-n` smart-splits the focused pane, `Alt-h/j/k/l` or Alt-arrows move focus, `Alt-[`/`Alt-]` switch screens, `Alt-t` opens a tab, and `Alt-=`/`Alt--` resize the focused split.
 
 Every pane draws a border box; the active pane's border is highlighted, the pane under the mouse gets a hover shade, and the box is where flashing notifications will hook in later. The top border doubles as an always-visible tab bar: tabs are numbered (`1`, `2`, ...; the process title follows the number when reported), clicking a title switches, dragging a tab reorders it within the pane or moves it to another pane's tab bar, the trailing `+` opens a new tab, and when tabs overflow, `‹`/`›` arrows (or the wheel over the bar) scroll them while the active tab stays visible. User-assigned tab names replace the generated number/title label outright. Drag a shared pane border to resize that split live; dragging a corner moves both intersecting splits, and outer pane edges are inert. Click anywhere in a pane to focus it. The status bar shows the active workspace's screens: click an entry to switch, the trailing `+` for a new screen; it spans only the pane region (not the sidebar). Right-click a pane for rename tab / new tab / split right / split down / close tab / close pane; right-click a workspace in the sidebar for rename/close; right-click a screen in the status bar for rename/close. Context menus and prompts draw muted borders; menu items keep one-cell side padding and the hover/selection highlight spans the full inner row. Right-press, drag, and release on a row activates that row. Prompts use readline-style editing with shortcut buttons (`Clear ^C`, `Cancel esc`, `OK ⏎`); Enter commits, Esc cancels, Ctrl-C clears, and empty tab/screen names fall back to defaults. Right-clicking while the prompt is open shakes it instead of opening a menu. The sidebar reserves two lines per workspace (name, then the active pane's title) under a `workspaces` header with a blank line after it and between entries; click an entry to switch, drag entries to reorder workspaces, `+ new workspace` to create one, and drag the sidebar's right border to resize it for the current session.
@@ -53,7 +61,7 @@ If no reusable browser is found and no Chrome binary is found, browser tab creat
 
 ## Configuration
 
-`~/.config/cmux/mux.json` (override with `CMUX_MUX_CONFIG`); every key is optional:
+`CMUX_MUX_CONFIG`, `$XDG_CONFIG_HOME/cmux/mux.json`, or `~/.config/cmux/mux.json`; every key is optional:
 
 ```json
 {
@@ -107,14 +115,15 @@ If no reusable browser is found and no Chrome binary is found, browser tab creat
 }
 ```
 
-Colors are `#rrggbb`, `#rgb`, or an xterm-256 index. The selection colors default to the user's Ghostty config (`selection-background`/`selection-foreground` from `~/.config/ghostty/config`), falling back to a dark grey. `sidebar_rail` controls the active workspace rail, `sidebar_active_bg` its two-row background, `tab_rail` the active tab chip rail, `tab_bg` inactive solid tab chips, and `tab_active_bg` overrides the focused/unfocused active tab chip backgrounds when set. Tabs are numbered `1 2 3…` by default; recognized agent programs (the `agents` list) surface after the number, `show_titles` restores full process titles, and a user-assigned tab name overrides both. `sidebar.max_width` defaults to `0` for unlimited, while live drag still leaves at least 40 columns for panes. `scrollbar.position` is `"column"` by default or `"border"` for the old right-border overlay. Browser config is optional: `chrome_binary` overrides binary discovery, `cdp_url` accepts `ws://...` or `http://host:port`, `discover` defaults to true, `discover_ports` defaults to `[9222]`, `user_data_dir` overrides the launched profile path, and `ephemeral` restores temporary-profile behavior. When `ephemeral` is true it takes precedence over `user_data_dir`: cmux creates and later deletes a fresh temp profile and never deletes the configured directory. Every prefix/modeless binding is remappable via `keys` (formats: `"c"`, `"%"`, `"ctrl+b"`, `"alt+enter"`, `"tab"`, `"backtab"`, `"pageup"`); values may be a string, an array of strings, or `"none"` to unbind. Set `"alt_shortcuts": false` to remove default Alt chords without blocking user-configured Alt chords. `1`-`9` stay fixed to tab selection. The old key name `"rename-pane"` is still accepted as an alias for `"rename-tab"`.
+Colors are `#rrggbb`, `#rgb`, or an xterm-256 index. The selection colors default to the user's Ghostty config (`selection-background`/`selection-foreground` from the platform paths above), falling back to a dark grey. `sidebar_rail` controls the active workspace rail, `sidebar_active_bg` its two-row background, `tab_rail` the active tab chip rail, `tab_bg` inactive solid tab chips, and `tab_active_bg` overrides the focused/unfocused active tab chip backgrounds when set. Tabs are numbered `1 2 3…` by default; recognized agent programs (the `agents` list) surface after the number, `show_titles` restores full process titles, and a user-assigned tab name overrides both. `sidebar.max_width` defaults to `0` for unlimited, while live drag still leaves at least 40 columns for panes. `scrollbar.position` is `"column"` by default or `"border"` for the old right-border overlay. Browser config is optional: `chrome_binary` overrides binary discovery, `cdp_url` accepts `ws://...` or `http://host:port`, `discover` defaults to true, `discover_ports` defaults to `[9222]`, `user_data_dir` overrides the launched profile path, and `ephemeral` restores temporary-profile behavior. When `ephemeral` is true it takes precedence over `user_data_dir`: cmux creates and later deletes a fresh temp profile and never deletes the configured directory. Every prefix/modeless binding is remappable via `keys` (formats: `"c"`, `"%"`, `"ctrl+b"`, `"alt+enter"`, `"tab"`, `"backtab"`, `"pageup"`); values may be a string, an array of strings, or `"none"` to unbind. Set `"alt_shortcuts": false` to remove default Alt chords without blocking user-configured Alt chords. `1`-`9` stay fixed to tab selection. The old key name `"rename-pane"` is still accepted as an alias for `"rename-tab"`.
 
 ## Control socket
 
-Every instance serves a JSON-lines protocol on a unix socket (default `$TMPDIR/cmux-mux-<uid>/<session>.sock`, also exported to children as `CMUX_MUX_SOCKET`). One request per line:
+Every instance serves a JSON-lines protocol on a unix socket (default under the platform runtime directory, also exported to children as `CMUX_MUX_SOCKET`). One request per line:
 
 ```bash
-SOCK=${TMPDIR:-/tmp}/cmux-mux-$(id -u)/main.sock
+SESSION=main
+SOCK=${CMUX_MUX_SOCKET:-${XDG_RUNTIME_DIR:-${TMPDIR:-/tmp}}/cmux-mux-$(id -u)/${SESSION}.sock}
 printf '%s\n' '{"id":1,"cmd":"identify"}' | nc -U "$SOCK"
 printf '%s\n' '{"id":2,"cmd":"list-workspaces"}' | nc -U "$SOCK"
 printf '%s\n' '{"id":3,"cmd":"send","surface":1,"text":"ls\r"}' | nc -U "$SOCK"

mux/crates/ghostty-vt-sys/build.rs

@@ -32,24 +32,33 @@ fn main() {
     // is an order of magnitude slower.
     let zig = env::var("ZIG").unwrap_or_else(|_| "zig".to_string());
     let prefix = out_dir.join("ghostty-vt");
-    let status = Command::new(&zig)
+    let target = env::var("TARGET").unwrap();
+    let host = env::var("HOST").unwrap();
+    let mut command = Command::new(&zig);
+    command
         .current_dir(&ghostty_dir)
         .arg("build")
         .arg("-Demit-lib-vt=true")
         .arg("-Demit-xcframework=false")
-        .arg("-Doptimize=ReleaseFast")
-        .arg("--prefix")
-        .arg(&prefix)
-        .status()
-        .unwrap_or_else(|e| {
-            panic!("failed to run `{zig} build` in {}: {e}", ghostty_dir.display())
-        });
+        .arg("-Doptimize=ReleaseFast");
+    if target != host {
+        if let Some(zig_target) = zig_target_for_rust_target(&target) {
+            command.arg(format!("-Dtarget={zig_target}"));
+        }
+    }
+    let status = command.arg("--prefix").arg(&prefix).status().unwrap_or_else(|e| {
+        panic!("failed to run `{zig} build` in {}: {e}", ghostty_dir.display())
+    });
     if !status.success() {
         panic!("zig build of libghostty-vt failed with {status}");
     }
 
     println!("cargo:rustc-link-search=native={}", prefix.join("lib").display());
-    println!("cargo:rustc-link-lib=static=ghostty-vt");
+    if target.contains("windows") {
+        println!("cargo:rustc-link-lib=static=ghostty-vt-static");
+    } else {
+        println!("cargo:rustc-link-lib=static=ghostty-vt");
+    }
 
     // Generate bindings from the public C header.
     let include_dir = ghostty_dir.join("include");
@@ -66,3 +75,12 @@ fn main() {
         .expect("bindgen failed for ghostty/vt.h");
     bindings.write_to_file(out_dir.join("bindings.rs")).expect("failed to write bindings.rs");
 }
+
+fn zig_target_for_rust_target(target: &str) -> Option<&'static str> {
+    match target {
+        "x86_64-pc-windows-gnu" => Some("x86_64-windows-gnu"),
+        "x86_64-pc-windows-msvc" => Some("x86_64-windows-msvc"),
+        "aarch64-pc-windows-msvc" => Some("aarch64-windows-msvc"),
+        _ => None,
+    }
+}