feat(release): ship a native Windows ARM64 build (#1043)

Release and nightly now build the desktop app for aarch64-pc-windows-msvc
alongside x64, publishing tty7-<version>-windows-arm64-setup.exe and
tty7-<version>-windows-arm64.zip.

- Cross-compiled on the x64 Windows runner, like server-windows' ARM64
  leg, and marked experimental until it has shipped once: a failure drops
  the ARM64 packages instead of holding up the release.
- Vendors Microsoft's arm64 ConPTY pair from the same package version as
  the x64 one, so ARM64 panes keep the OSC 11 fix (#345).
- Each Windows package bundles the WSL server for its own architecture.
- The installer's architecture comes in as a define: x64compatible for the
  x64 build (still installable on ARM64 under emulation), arm64 for the
  native one. One AppId, so either upgrades the other.
- The in-app updater on an ARM64 build asks for the arm64 packages; an x64
  build under emulation keeps taking x64 ones.

Claude-Session: https://claude.ai/code/session_011mDkkQhwx4RJJBHee3yVpq

.github/scripts/bundle-windows.ps1

@@ -50,7 +50,7 @@ Copy-Item README.md "$Stage/README.md"
 # swallows a pane's OSC 11 background query (#345); this pair forwards it. The
 # two files are one unit, so a missing half is an error rather than a warning.
 # See assets/windows/conpty/README.md.
-$ConptyArch = @{ 'x86_64-pc-windows-msvc' = 'x64' }[$Target]
+$ConptyArch = @{ 'x86_64-pc-windows-msvc' = 'x64'; 'aarch64-pc-windows-msvc' = 'arm64' }[$Target]
 if (-not $ConptyArch) { throw "no vendored ConPTY for $Target - see assets/windows/conpty/README.md" }
 foreach ($File in 'conpty.dll', 'OpenConsole.exe') {
     $Source = "assets/windows/conpty/$ConptyArch/$File"
@@ -68,9 +68,14 @@ Copy-Item "assets/windows/conpty/LICENSE.txt" "$Stage/LICENSE-ConPTY.txt"
 # naming the directories it searched.
 #
 # The *filename* is a contract too, not just the directory: `wsl.rs` looks for
-# `<dir>/<asset name>`, so this string has to stay whatever
-# `install::asset::ASSET_X86_64` says it is.
-$ServerAsset = "tty7-server-linux-x86_64-musl"
+# `<dir>/<asset name>`, so these strings have to stay whatever
+# `install::asset::ASSET_X86_64` / `ASSET_AARCH64` say they are. A WSL distro
+# runs the host's architecture, so each package carries the one that matches it.
+$ServerAsset = @{
+    'x86_64-pc-windows-msvc'  = 'tty7-server-linux-x86_64-musl'
+    'aarch64-pc-windows-msvc' = 'tty7-server-linux-aarch64-musl'
+}[$Target]
+if (-not $ServerAsset) { throw "no bundled WSL server asset known for $Target" }
 $ServerSrc = "bundled-server/$ServerAsset"
 if (Test-Path $ServerSrc) {
     New-Item -ItemType Directory -Force -Path "$Stage/server" | Out-Null
@@ -94,6 +99,15 @@ if ($PackageUpdater) {
     Set-Content -Path "$Stage/.tty7-inno-install" -Value 'inno-v1' -NoNewline -Encoding ascii
 }
 
+# Inno's architecture identifier for this payload. `x64compatible` also admits
+# ARM64 Windows, which runs the x64 build under emulation — so an ARM64 machine
+# can take either installer, and both upgrade the same install (one AppId).
+$InstallArch = @{
+    'x86_64-pc-windows-msvc'  = 'x64compatible'
+    'aarch64-pc-windows-msvc' = 'arm64'
+}[$Target]
+if (-not $InstallArch) { throw "no Inno architecture known for $Target" }
+
 # Installer, built from the same staged payload. ISCC is on PATH on GitHub's
 # windows-latest image; fall back to the default install location.
 $Iscc = (Get-Command ISCC.exe -ErrorAction SilentlyContinue).Source
@@ -104,6 +118,7 @@ if (-not $Iscc) { $Iscc = "${env:ProgramFiles(x86)}\Inno Setup 6\ISCC.exe" }
     "/DStageDir=$((Resolve-Path $Stage).Path)" `
     "/DOutputDir=$((Resolve-Path dist).Path)" `
     "/DOutputName=$Name-setup" `
+    "/DArchitectures=$InstallArch" `
     .github/scripts/windows-installer.iss
 if ($LASTEXITCODE -ne 0) { throw "ISCC exited with $LASTEXITCODE" }
 

.github/scripts/windows-installer.iss

@@ -7,6 +7,7 @@
 ;   /DStageDir=<abs path>   staged payload (app, CLI, updater, marker, resources)
 ;   /DOutputDir=<abs path>  where the setup exe is written
 ;   /DOutputName=<basename> setup exe filename, without ".exe"
+;   /DArchitectures=<id>    Inno architecture: x64compatible or arm64
 ;
 ; Defaults to a per-user install ({localappdata}\Programs\tty7 — no UAC
 ; prompt), with an "install for all users" escape hatch in the dialog. The
@@ -19,6 +20,9 @@
 #ifndef VersionInfoVersion
   #error Missing /DVersionInfoVersion — this script is meant to be compiled via bundle-windows.ps1
 #endif
+#ifndef Architectures
+  #error Missing /DArchitectures — this script is meant to be compiled via bundle-windows.ps1
+#endif
 
 [Setup]
 ; Never change AppId: it is how Windows ties upgrades + the uninstall entry
@@ -35,8 +39,8 @@ DefaultDirName={autopf}\tty7
 DisableProgramGroupPage=yes
 PrivilegesRequired=lowest
 PrivilegesRequiredOverridesAllowed=dialog
-ArchitecturesAllowed=x64compatible
-ArchitecturesInstallIn64BitMode=x64compatible
+ArchitecturesAllowed={#Architectures}
+ArchitecturesInstallIn64BitMode={#Architectures}
 MinVersion=10.0
 LicenseFile={#StageDir}\LICENSE.txt
 SetupIconFile=..\..\assets\favicon.ico

.github/workflows/nightly.yml

@@ -84,11 +84,23 @@ jobs:
             os: windows
             arch: x86_64
             target: x86_64-pc-windows-msvc
+            wsl-server: tty7-server-linux-x86_64-musl
+          # Cross-compiled from the x64 runner, like `server-windows`'s ARM64
+          # leg. Experimental until it has shipped once: a failure here drops
+          # the ARM64 packages from the release instead of holding it up, and
+          # ARM64 machines still have the x64 build under emulation.
+          - runner: windows-latest
+            os: windows
+            arch: arm64
+            target: aarch64-pc-windows-msvc
+            wsl-server: tty7-server-linux-aarch64-musl
+            experimental: true
           - runner: ubuntu-latest
             os: linux
             arch: x86_64
             target: x86_64-unknown-linux-gnu
     runs-on: ${{ matrix.runner }}
+    continue-on-error: ${{ matrix.experimental == true }}
     steps:
       - name: Checkout tty7
         uses: actions/checkout@v4
@@ -121,6 +133,9 @@ jobs:
       - uses: Swatinem/rust-cache@v2
         with:
           workspaces: tty7
+          # Two Windows legs share a runner OS; without the target in the key
+          # they would overwrite each other's cache.
+          key: ${{ matrix.target }}
 
       # The updater ships on every GUI platform now: inside the macOS bundle,
       # beside the Windows app, and inside the Linux AppImage.
@@ -200,7 +215,7 @@ jobs:
         continue-on-error: true
         uses: actions/download-artifact@v8
         with:
-          name: nightly-tty7-server-linux-x86_64-musl
+          name: nightly-${{ matrix.wsl-server }}
           path: tty7/bundled-server
 
       - name: Package Windows installer + zip

.github/workflows/release.yml

@@ -35,11 +35,23 @@ jobs:
             os: windows
             arch: x86_64
             target: x86_64-pc-windows-msvc
+            wsl-server: tty7-server-linux-x86_64-musl
+          # Cross-compiled from the x64 runner, like `server-windows`'s ARM64
+          # leg. Experimental until it has shipped once: a failure here drops
+          # the ARM64 packages from the release instead of holding it up, and
+          # ARM64 machines still have the x64 build under emulation.
+          - runner: windows-latest
+            os: windows
+            arch: arm64
+            target: aarch64-pc-windows-msvc
+            wsl-server: tty7-server-linux-aarch64-musl
+            experimental: true
           - runner: ubuntu-latest
             os: linux
             arch: x86_64
             target: x86_64-unknown-linux-gnu
     runs-on: ${{ matrix.runner }}
+    continue-on-error: ${{ matrix.experimental == true }}
     steps:
       - name: Checkout tty7
         uses: actions/checkout@v4
@@ -69,6 +81,9 @@ jobs:
       - uses: Swatinem/rust-cache@v2
         with:
           workspaces: tty7
+          # Two Windows legs share a runner OS; without the target in the key
+          # they would overwrite each other's cache.
+          key: ${{ matrix.target }}
 
       # `--locked` because a release must ship the dependency set the tag
       # recorded, not whatever cargo would re-resolve at build time. Safe here
@@ -147,7 +162,7 @@ jobs:
         continue-on-error: true
         uses: actions/download-artifact@v8
         with:
-          name: release-tty7-server-linux-x86_64-musl
+          name: release-${{ matrix.wsl-server }}
           path: tty7/bundled-server
 
       - name: Package Windows installer + zip
@@ -388,9 +403,10 @@ jobs:
   # redistributable — which a headless server is the likeliest machine to lack.
   # Symbols are stripped through the profile instead.
   #
-  # ARM64 is new ground for this repository's Windows builds (the app itself
-  # ships x64 only), so its leg may fail without holding up the release; an
-  # ARM64 host then gets a clear "could not download" instead of a server.
+  # ARM64 is new ground for this repository's Windows builds (the app's own
+  # ARM64 leg in `build` is experimental too), so its leg may fail without
+  # holding up the release; an ARM64 host then gets a clear "could not
+  # download" instead of a server.
   server-windows:
     strategy:
       fail-fast: false

assets/windows/conpty/README.md

@@ -46,8 +46,11 @@ curl.exe -sL -o conpty.zip "https://api.nuget.org/v3-flatcontainer/microsoft.win
 Expand-Archive conpty.zip -DestinationPath conpty-pkg
 Copy-Item conpty-pkg/runtimes/win-x64/native/conpty.dll        x64/conpty.dll
 Copy-Item conpty-pkg/build/native/runtimes/x64/OpenConsole.exe x64/OpenConsole.exe
+Copy-Item conpty-pkg/runtimes/win-arm64/native/conpty.dll        arm64/conpty.dll
+Copy-Item conpty-pkg/build/native/runtimes/arm64/OpenConsole.exe arm64/OpenConsole.exe
 ```
 
-Only `x86_64-pc-windows-msvc` is released today, so only `x64/` is vendored. The
-package also carries `arm64` and `x86`; adding an architecture means adding the
-directory here and one `Copy-Item` in `.github/scripts/bundle-windows.ps1`.
+`x64/` and `arm64/` match the two released Windows targets
+(`x86_64-pc-windows-msvc`, `aarch64-pc-windows-msvc`). The package also carries
+`x86`; adding an architecture means adding the directory here, one arm in
+`build.rs`, and one entry in `.github/scripts/bundle-windows.ps1`'s `$ConptyArch`.

build.rs

@@ -31,8 +31,9 @@ fn stage_bundled_conpty() {
     let arch = std::env::var("CARGO_CFG_TARGET_ARCH").unwrap_or_default();
     let vendored = match arch.as_str() {
         "x86_64" => "x64",
-        // Every other Windows architecture is unreleased, so nothing is
-        // vendored for it and the in-box conhost stays in charge.
+        "aarch64" => "arm64",
+        // 32-bit Windows is unreleased, so nothing is vendored for it and the
+        // in-box conhost stays in charge.
         _ => return,
     };
     let source = PathBuf::from("assets/windows/conpty").join(vendored);

docs/getting-started/installation.mdx

@@ -27,12 +27,17 @@ AppImage bundles its own X11/Wayland/font libraries.
   </Tab>
 
   <Tab title="Windows">
-    Two shapes, both x86-64:
+    Two shapes, each built for x86-64 (`x86_64`) and ARM64 (`arm64`, e.g.
+    Snapdragon laptops):
 
     | File | Use it when |
     |---|---|
-    | `tty7-<version>-windows-x86_64-setup.exe` | You want a normal install with Start-menu entries and an uninstaller. |
-    | `tty7-<version>-windows-x86_64.zip` | You want it portable — unzip anywhere and run `tty7-app.exe`. |
+    | `tty7-<version>-windows-<arch>-setup.exe` | You want a normal install with Start-menu entries and an uninstaller. |
+    | `tty7-<version>-windows-<arch>.zip` | You want it portable — unzip anywhere and run `tty7-app.exe`. |
+
+    The x86-64 build also runs on ARM64 Windows under emulation, but the
+    `arm64` one is native. Installing either over the other upgrades the same
+    install.
 
     The installer offers one optional setup task, off by default: **Add "Open in
     tty7" to the folder context menu**. It writes shell verbs under `HKCU`, so

src/core/update.rs

@@ -2687,8 +2687,14 @@ impl WindowsUpdateLayout {
 
 #[cfg(target_os = "windows")]
 fn windows_package_for_layout(version: &str, layout: &WindowsUpdateLayout) -> Option<String> {
+    // Labelled like the macOS packages (`arm64`), not like the server assets
+    // (`aarch64`): these are the desktop app's names. An x64 build running
+    // under emulation on ARM64 keeps taking x64 packages — switching it to
+    // the native build is the user's reinstall, not something an update does.
     let arch = if cfg!(target_arch = "x86_64") {
         "x86_64"
+    } else if cfg!(target_arch = "aarch64") {
+        "arm64"
     } else {
         return None;
     };
@@ -3732,12 +3738,20 @@ mod tests {
         assert_eq!(
             windows_package_for_layout("26.8.2", &WindowsUpdateLayout::Inno(directory.clone()))
                 .as_deref(),
-            Some("tty7-26.8.2-windows-x86_64-setup.exe")
+            Some(if cfg!(target_arch = "aarch64") {
+                "tty7-26.8.2-windows-arm64-setup.exe"
+            } else {
+                "tty7-26.8.2-windows-x86_64-setup.exe"
+            })
         );
         assert_eq!(
             windows_package_for_layout("26.8.2", &WindowsUpdateLayout::Portable(directory))
                 .as_deref(),
-            Some("tty7-26.8.2-windows-x86_64.zip")
+            Some(if cfg!(target_arch = "aarch64") {
+                "tty7-26.8.2-windows-arm64.zip"
+            } else {
+                "tty7-26.8.2-windows-x86_64.zip"
+            })
         );
     }