Release 0.11.1

Co-Authored-By: Claude Opus 5.5 <[email protected]>

.github/workflows/ci.yml

@@ -306,11 +306,38 @@ jobs:
       - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
         with:
           key: windows-fxc
-      - run: cargo test -p solidcraft-gpu --profile ci --locked
+      # One test at a time: WARP's shader JIT crashes now and then (a null read in
+      # d3d10warp.dll's JIT optimizer, about 1 run in 60) when several devices compile compute
+      # pipelines at once, which the parallel tests do. Minidumps showed it in WARP itself, not
+      # in SolidCraft or FXC; serial runs never hit it.
+      - run: cargo test -p solidcraft-gpu --profile ci --locked -- --test-threads=1
+
+  # The Windows app starts D3D12 first and only the backend it uses (a Vulkan driver crashed the
+  # app at startup on Intel). Start the real app on the runner (its D3D12 adapter is WARP) with
+  # several saved settings and safe mode, and check each draws a frame and quits cleanly.
+  windows-startup:
+    name: Windows app startup
+    needs: changes
+    if: needs.changes.outputs.native == 'true'
+    runs-on: windows-latest
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@6323deb102c322ba6fcbdcafc7e3dddab59af2b6 # v2.9.2
+        with:
+          key: windows-startup
+      - name: Backend order and probing on Windows
+        run: cargo test -p solidcraft --profile ci --locked -- startup::tests
+      - name: Build the app
+        run: cargo build -p solidcraft --profile ci --locked
+      - name: Start the app under different settings
+        shell: pwsh
+        run: tools/windows-startup-smoke.ps1 -Exe target/ci/solidcraft.exe
 
   # Preserve the existing check name for branch protection, including docs-only PRs.
   ci:
-    needs: [changes, checks, clippy, build-tests, tests, doc-tests, oracle, windows-fxc]
+    needs: [changes, checks, clippy, build-tests, tests, doc-tests, oracle, windows-fxc, windows-startup]
     if: always()
     runs-on: ubuntu-24.04
     steps:
@@ -325,6 +352,7 @@ jobs:
           DOCS: ${{ needs.doc-tests.result }}
           ORACLE: ${{ needs.oracle.result }}
           WINDOWS_FXC: ${{ needs.windows-fxc.result }}
+          WINDOWS_STARTUP: ${{ needs.windows-startup.result }}
         run: |
           test "$CHANGES" = success
           test "$CHECKS" = success
@@ -335,6 +363,7 @@ jobs:
             test "$DOCS" = success
             test "$ORACLE" = success
             test "$WINDOWS_FXC" = success
+            test "$WINDOWS_STARTUP" = success
           fi
 
   wasm:

Cargo.lock

@@ -3445,7 +3445,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "block2 0.6.2",
  "eframe",
@@ -3471,7 +3471,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-cli"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "serde_json",
  "solidcraft-engine",
@@ -3480,7 +3480,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-doc"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "log",
  "serde",
@@ -3495,7 +3495,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-engine"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "log",
  "serde",
@@ -3511,7 +3511,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-geom"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "serde",
  "serde_json",
@@ -3520,7 +3520,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-gpu"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "log",
  "naga",
@@ -3533,7 +3533,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-io"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "quick-xml",
  "serde",
@@ -3548,7 +3548,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-kernel"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "log",
  "rayon",
@@ -3566,7 +3566,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-mcp"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "serde_json",
  "solidcraft-engine",
@@ -3574,7 +3574,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-render"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "image",
  "serde",
@@ -3584,7 +3584,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-sketch"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "serde",
  "serde_json",
@@ -3595,7 +3595,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-ui-egui"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "egui",
  "egui-wgpu",
@@ -3616,7 +3616,7 @@ dependencies = [
 
 [[package]]
 name = "solidcraft-web"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "eframe",
  "egui",
@@ -5094,7 +5094,7 @@ checksum = "e450f9b2ed1dff33c94c12589a87338689467b9c4f5d8a5710bd09a847d2c8a7"
 
 [[package]]
 name = "xtask"
-version = "0.11.0"
+version = "0.11.1"
 dependencies = [
  "serde_json",
  "sha2",

Cargo.toml

@@ -5,7 +5,7 @@ members = ["crates/*", "apps/*", "xtask"]
 exclude = ["vendor"]
 
 [workspace.package]
-version = "0.11.0"
+version = "0.11.1"
 edition = "2024"
 license = "MIT OR Apache-2.0"
 rust-version = "1.95"

apps/solidcraft/Cargo.toml

@@ -29,6 +29,8 @@ log = { workspace = true }
 rfd = { workspace = true }
 # Checks eframe's settings file (app.ron) before eframe reads it (src/startup.rs).
 ron = "0.12"
+# Waits for wgpu's adapter list when choosing the graphics backend before the window opens.
+pollster = { workspace = true }
 getrandom = "0.3"
 # The update check (docs/updates.md): HTTPS with rustls, certificates from the operating system.
 ureq = { version = "3.4", default-features = false, features = ["rustls-no-provider", "platform-verifier"] }
@@ -50,8 +52,5 @@ block2 = "0.6"
 [target.'cfg(all(unix, not(target_os = "macos")))'.dependencies]
 winit = { version = "0.30", default-features = false, features = ["x11"] }
 
-[dev-dependencies]
-pollster = { workspace = true }
-
 [build-dependencies]
 embed-resource = "3.0.11"

apps/solidcraft/src/main.rs

@@ -276,11 +276,19 @@ fn adopt_settings(
     Ok(())
 }
 
+/// `graphics.json`, read before the window opens.
+fn graphics() -> Option<serde_json::Value> {
+    graphics_path().and_then(|p| std::fs::read_to_string(p).ok()).and_then(|s| serde_json::from_str::<serde_json::Value>(&s).ok())
+}
+
+/// The graphics backend preference (`graphics.json`'s `backend`: `auto`, `dx12`, `vulkan`, `gl`).
+fn backend_preference() -> Option<String> {
+    graphics().and_then(|v| v.get("backend").and_then(serde_json::Value::as_str).map(str::to_string))
+}
+
 /// Anti-aliasing samples from Preferences (4 when unset).
 fn msaa() -> u16 {
-    graphics_path()
+    graphics()
-        .and_then(|p| std::fs::read_to_string(p).ok())
-        .and_then(|s| serde_json::from_str::<serde_json::Value>(&s).ok())
         .and_then(|v| v.get("msaa").and_then(serde_json::Value::as_u64))
         .and_then(|m| u16::try_from(m).ok())
         .filter(|m| [1, 2, 4, 8].contains(m))
@@ -399,7 +407,7 @@ fn main() -> eframe::Result {
             settings.as_ref().map(|d| d.join("app.ron"))
         },
         persist_window: !safe_mode,
-        wgpu_options: wgpu_options(cpu_renderer),
+        wgpu_options: wgpu_options(cpu_renderer, if safe_mode { None } else { backend_preference() }.as_deref()),
         ..Default::default()
     };
     #[cfg(all(unix, not(target_os = "macos")))]
@@ -504,11 +512,20 @@ fn main() -> eframe::Result {
     }
 }
 
-/// The renderer settings: with `cpu`, the software adapter (WARP, lavapipe, llvmpipe).
+/// The renderer settings: with `cpu`, the software adapter (WARP, lavapipe, llvmpipe). The
-fn wgpu_options(cpu: bool) -> eframe::egui_wgpu::WgpuConfiguration {
+/// backends come from `startup::choose_backends` (on Windows D3D12 first, and only the backend
+/// in use is started); `preference` is `graphics.json`'s `backend`.
+fn wgpu_options(cpu: bool, preference: Option<&str>) -> eframe::egui_wgpu::WgpuConfiguration {
     let mut options = eframe::egui_wgpu::WgpuConfiguration::default();
-    if cpu && let eframe::egui_wgpu::WgpuSetup::CreateNew(setup) = &mut options.wgpu_setup {
+    if let eframe::egui_wgpu::WgpuSetup::CreateNew(setup) = &mut options.wgpu_setup {
-        setup.native_adapter_selector = Some(std::sync::Arc::new(startup::pick_cpu_adapter));
+        let env_set = std::env::var(startup::WGPU_BACKEND_ENV).is_ok_and(|v| !v.trim().is_empty());
+        if let Some(backends) = startup::choose_backends(cfg!(target_os = "windows"), env_set, cpu, preference, startup::has_hardware_adapter) {
+            eprintln!("SolidCraft graphics: starting {backends:?}");
+            setup.instance_descriptor.backends = backends;
+        }
+        if cpu {
+            setup.native_adapter_selector = Some(std::sync::Arc::new(startup::pick_cpu_adapter));
+        }
     }
     options
 }

apps/solidcraft/src/startup.rs

@@ -110,6 +110,68 @@ pub fn pick_cpu_adapter(adapters: &[eframe::wgpu::Adapter], surface: Option<&efr
         })
 }
 
+/// `WGPU_BACKEND`: when set, wgpu picks the backends from it and the order below is not used.
+pub const WGPU_BACKEND_ENV: &str = "WGPU_BACKEND";
+
+/// The graphics backends to start with, or `None` to leave it to wgpu (`WGPU_BACKEND`, or all
+/// the backends it was built with).
+///
+/// On Windows, D3D12 comes first, then Vulkan, then OpenGL, and only the first one with a
+/// hardware adapter is started at all. wgpu would otherwise start Vulkan, D3D12 and OpenGL
+/// together and prefer Vulkan, and starting Vulkan loads every installed Vulkan driver: Intel's
+/// (`igvk64.dll`) crashed SolidCraft at startup that way, inside the driver, before anything
+/// could be reported. D3D12 is Windows' own graphics API, the one its drivers are tested with.
+/// `has_hardware(backends)` says whether those backends have an adapter that isn't software
+/// (it is only asked about the backends being tried, one at a time).
+///
+/// - `WGPU_BACKEND` set (`env_set`): `None`, whatever it says wins.
+/// - The software renderer (`cpu`, safe mode): D3D12 alone on Windows (WARP); `None` elsewhere.
+/// - `preference` (`graphics.json`'s `backend`: `dx12`, `vulkan`, `gl` or a comma list; `auto`
+///   or empty for the order above): those backends, on any system.
+/// - Elsewhere than Windows: `None`.
+/// - No hardware adapter at all: D3D12 (WARP, Windows' software renderer).
+pub fn choose_backends(
+    windows: bool,
+    env_set: bool,
+    cpu: bool,
+    preference: Option<&str>,
+    mut has_hardware: impl FnMut(eframe::wgpu::Backends) -> bool,
+) -> Option<eframe::wgpu::Backends> {
+    use eframe::wgpu::Backends;
+    if env_set {
+        return None;
+    }
+    if cpu {
+        return windows.then_some(Backends::DX12);
+    }
+    if let Some(p) = preference.map(str::trim).filter(|p| !p.is_empty() && !p.eq_ignore_ascii_case("auto")) {
+        let chosen = Backends::from_comma_list(p);
+        if !chosen.is_empty() {
+            return Some(chosen);
+        }
+        log::warn!("graphics: unknown backend preference `{p}`; using the default order");
+    }
+    if !windows {
+        return None;
+    }
+    Some(WINDOWS_ORDER.into_iter().find(|b| has_hardware(*b)).unwrap_or(Backends::DX12))
+}
+
+/// The order backends are tried in on Windows.
+pub const WINDOWS_ORDER: [eframe::wgpu::Backends; 3] = [eframe::wgpu::Backends::DX12, eframe::wgpu::Backends::VULKAN, eframe::wgpu::Backends::GL];
+
+/// Whether `backends` (started on their own, nothing else) have a hardware adapter.
+pub fn has_hardware_adapter(backends: eframe::wgpu::Backends) -> bool {
+    let mut desc = eframe::wgpu::InstanceDescriptor::new_without_display_handle();
+    desc.backends = backends;
+    desc.flags = eframe::wgpu::InstanceFlags::from_build_config().with_env();
+    let instance = eframe::wgpu::Instance::new(desc);
+    let adapters = pollster::block_on(instance.enumerate_adapters(backends));
+    let found: Vec<String> = adapters.iter().map(|a| format!("{} ({:?})", a.get_info().name, a.get_info().device_type)).collect();
+    log::info!("graphics: {backends:?} adapters: {found:?}");
+    adapters.iter().any(|a| a.get_info().device_type != eframe::wgpu::DeviceType::Cpu)
+}
+
 /// The message shown when no window could be opened at all.
 pub fn no_window_message(error: &str, settings: Option<&Path>) -> String {
     let folder = settings.map(|d| d.display().to_string()).unwrap_or_else(|| "the SolidCraft settings folder".into());
@@ -182,6 +244,65 @@ mod tests {
         let _ = std::fs::remove_dir_all(&d);
     }
 
+    #[test]
+    fn windows_starts_d3d12_first_and_vulkan_only_when_d3d12_has_no_gpu() {
+        use eframe::wgpu::Backends;
+        let probe = |with: &'static [Backends]| {
+            move |b: Backends| {
+                assert!(b == Backends::DX12 || b == Backends::VULKAN || b == Backends::GL, "one backend at a time: {b:?}");
+                with.contains(&b)
+            }
+        };
+        // D3D12 works: Vulkan and OpenGL are never even asked about (starting Vulkan loads
+        // its drivers, which is what crashed).
+        let mut asked = Vec::new();
+        let chosen = choose_backends(true, false, false, None, |b| {
+            asked.push(b);
+            b == Backends::DX12
+        });
+        assert_eq!(chosen, Some(Backends::DX12));
+        assert_eq!(asked, [Backends::DX12]);
+        // Everything works: still D3D12 alone.
+        assert_eq!(choose_backends(true, false, false, None, probe(&[Backends::DX12, Backends::VULKAN, Backends::GL])), Some(Backends::DX12));
+        // No D3D12 hardware adapter: Vulkan, else OpenGL, else D3D12's software adapter (WARP).
+        assert_eq!(choose_backends(true, false, false, None, probe(&[Backends::VULKAN, Backends::GL])), Some(Backends::VULKAN));
+        assert_eq!(choose_backends(true, false, false, None, probe(&[Backends::GL])), Some(Backends::GL));
+        assert_eq!(choose_backends(true, false, false, None, probe(&[])), Some(Backends::DX12));
+        // `auto` and blanks are the default order.
+        assert_eq!(choose_backends(true, false, false, Some(" auto "), probe(&[Backends::DX12])), Some(Backends::DX12));
+        assert_eq!(choose_backends(true, false, false, Some(""), probe(&[Backends::GL])), Some(Backends::GL));
+    }
+
+    #[test]
+    fn wgpu_backend_the_preference_and_the_software_renderer_override_the_order() {
+        use eframe::wgpu::Backends;
+        let never = |b: Backends| -> bool { panic!("no probing expected, asked about {b:?}") };
+        // WGPU_BACKEND: wgpu reads it itself, nothing is probed.
+        assert_eq!(choose_backends(true, true, false, Some("gl"), never), None);
+        assert_eq!(choose_backends(true, true, true, None, never), None);
+        // The software renderer (safe mode, the retry): WARP through D3D12 alone, never Vulkan.
+        assert_eq!(choose_backends(true, false, true, Some("vulkan"), never), Some(Backends::DX12));
+        assert_eq!(choose_backends(false, false, true, None, never), None);
+        // The preference, on any system, without probing.
+        assert_eq!(choose_backends(true, false, false, Some("vulkan"), never), Some(Backends::VULKAN));
+        assert_eq!(choose_backends(true, false, false, Some("GL"), never), Some(Backends::GL));
+        assert_eq!(choose_backends(true, false, false, Some("dx12,vulkan"), never), Some(Backends::DX12 | Backends::VULKAN));
+        assert_eq!(choose_backends(false, false, false, Some("vulkan"), never), Some(Backends::VULKAN));
+        // An unknown preference is the default order.
+        assert_eq!(choose_backends(true, false, false, Some("glide"), |b| b == Backends::DX12), Some(Backends::DX12));
+        // Elsewhere: wgpu's own choice.
+        assert_eq!(choose_backends(false, false, false, None, never), None);
+        assert_eq!(choose_backends(false, false, false, Some("auto"), never), None);
+    }
+
+    #[test]
+    fn probing_a_backend_alone_never_panics() {
+        // Whatever this machine has (often nothing): an answer, not a crash.
+        for b in WINDOWS_ORDER {
+            let _ = has_hardware_adapter(b);
+        }
+    }
+
     #[test]
     fn the_message_names_the_settings_folder_and_safe_mode() {
         let m = no_window_message("no adapter", Some(Path::new("/x/SolidCraft")));

crates/ui-egui/src/prefs.rs

@@ -629,7 +629,14 @@ pub fn show_mm_bare(app: &SolveApp, v: f64) -> String {
 /// change while it is open).
 fn save_graphics(app: &SolveApp) {
     if let Some(path) = &app.services.graphics_path {
-        let _ = std::fs::write(path, json!({ "msaa": app.preferences.msaa }).to_string());
+        // Other settings in the file (the graphics `backend`) stay as they are.
+        let mut graphics = std::fs::read_to_string(path)
+            .ok()
+            .and_then(|s| serde_json::from_str::<serde_json::Value>(&s).ok())
+            .filter(serde_json::Value::is_object)
+            .unwrap_or_else(|| json!({}));
+        graphics["msaa"] = json!(app.preferences.msaa);
+        let _ = std::fs::write(path, graphics.to_string());
     }
 }
 
@@ -1215,10 +1222,12 @@ mod tests {
         // WebGPU's guarantee for the surface format: 8x saved, the device can only do 1x and 4x.
         app.msaa_supported = vec![1, 4];
         app.preferences.msaa = 8;
+        std::fs::write(&path, r#"{"msaa":8,"backend":"vulkan"}"#).unwrap();
         check_msaa(&mut app, 8);
         assert_eq!(app.preferences.msaa, 4);
         let saved: serde_json::Value = serde_json::from_str(&std::fs::read_to_string(&path).unwrap_or_default()).unwrap_or_default();
         assert_eq!(saved["msaa"], 4);
+        assert_eq!(saved["backend"], "vulkan", "the backend preference is kept");
         assert_eq!(app.settings_reset, [SettingReset::Msaa { requested: 8, reset: 4, supported: vec![1, 4] }]);
         assert_eq!(
             app.settings_reset[0].message(),

docs/book/src/guide/troubleshooting.md

@@ -62,6 +62,28 @@ saying what failed (earlier versions closed without a word). Things to try:
 - Run `solidcraft --crash-log` to list recent crash reports, and attach the newest one to an
   issue.
 
+## SolidCraft closes right away on Windows
+
+A graphics driver can crash the app while it starts, before SolidCraft can show anything (an
+old Intel Vulkan driver, `igvk64.dll`, did). Windows' Event Viewer names the driver under
+*Windows Logs › Application* ("Faulting module name").
+
+From 0.11.1, SolidCraft on Windows starts Direct3D 12 first and loads no other graphics API
+when Direct3D 12 has a graphics card; Vulkan and then OpenGL are tried only on a computer
+without one. Earlier versions started Vulkan, Direct3D 12 and OpenGL together and preferred
+Vulkan. To choose the graphics API yourself, in any version, open a Command Prompt and start
+SolidCraft from it:
+
+```
+set WGPU_BACKEND=dx12
+"C:\Program Files\SolidCraft\solidcraft.exe"
+```
+
+`vulkan` and `gl` are the other choices. `setx WGPU_BACKEND dx12` keeps it for apps started
+from the Start menu after you sign in again. From 0.11.1 the setting can also live in
+`graphics.json` in the settings folder, as `{"msaa": 4, "backend": "dx12"}` (`auto` is the
+order above). Safe mode ignores it and always uses the software renderer.
+
 ## A design saved by 0.10 won't open in an older version
 
 Designs saved by a newer SolidCraft use a newer file format. Older versions refuse them with

tools/windows-startup-smoke.ps1

@@ -0,0 +1,91 @@
+# Start the Windows app under different graphics settings and check each one gets its window up,
+# draws a frame and quits cleanly, with no crash report. The CI runner has no GPU: its D3D12 adapter
+# is WARP, so this exercises the backend order's fallback and the D3D12 path end to end.
+#
+# Usage: tools/windows-startup-smoke.ps1 -Exe target\ci\solidcraft.exe
+param([Parameter(Mandatory = $true)][string]$Exe)
+$ErrorActionPreference = 'Stop'
+
+$cases = @(
+    @{ Name = 'default order'; Graphics = $null; Env = @{}; Args = @(); Expect = 'graphics: Dx12' },
+    @{ Name = 'saved 8x anti-aliasing'; Graphics = '{"msaa":8}'; Env = @{}; Args = @(); Expect = '(requested 8x)' },
+    @{ Name = 'saved 2x, backend preference dx12'; Graphics = '{"msaa":2,"backend":"dx12"}'; Env = @{}; Args = @(); Expect = '(requested 2x)' },
+    @{ Name = 'damaged graphics.json'; Graphics = '{"msaa":'; Env = @{}; Args = @(); Expect = 'graphics: Dx12' },
+    @{ Name = 'WGPU_BACKEND=dx12 with FXC'; Graphics = $null; Env = @{ WGPU_BACKEND = 'dx12'; WGPU_DX12_COMPILER = 'fxc' }; Args = @(); Expect = 'graphics: Dx12' },
+    @{ Name = 'safe mode'; Graphics = '{"msaa":8,"backend":"vulkan"}'; Env = @{}; Args = @('--safe-mode'); Expect = 'graphics: Dx12' }
+)
+
+$failed = @()
+$port = 47811
+foreach ($case in $cases) {
+    $port += 1
+    $root = Join-Path $env:RUNNER_TEMP ("smoke-" + $port)
+    Remove-Item -Recurse -Force $root -ErrorAction SilentlyContinue
+    # eframe asks Windows for the roaming folder (not %APPDATA%), so the settings go in the
+    # runner's real one, emptied for each case.
+    $settings = Join-Path ([Environment]::GetFolderPath('ApplicationData')) 'SolidCraft\data'
+    Remove-Item -Recurse -Force $settings -ErrorAction SilentlyContinue
+    $local = Join-Path $root 'local'
+    $crashes = Join-Path $root 'crashes'
+    New-Item -ItemType Directory -Force $settings, $local, $crashes | Out-Null
+    if ($case.Graphics) { Set-Content -NoNewline -Path (Join-Path $settings 'graphics.json') -Value $case.Graphics }
+    $token = -join ((1..64) | ForEach-Object { '{0:x}' -f (Get-Random -Maximum 16) })
+
+    $psi = New-Object System.Diagnostics.ProcessStartInfo
+    $psi.FileName = (Resolve-Path $Exe).Path
+    foreach ($a in (@('--sample', '--control', "$port") + $case.Args)) { [void]$psi.ArgumentList.Add($a) }
+    $psi.UseShellExecute = $false
+    $psi.RedirectStandardError = $true
+    $psi.RedirectStandardOutput = $true
+    $psi.Environment['LOCALAPPDATA'] = $local
+    $psi.Environment['SOLIDCRAFT_CRASH_DIR'] = $crashes
+    $psi.Environment['SOLIDCRAFT_CONTROL_TOKEN'] = $token
+    $psi.Environment.Remove('WGPU_BACKEND') | Out-Null
+    $psi.Environment.Remove('WGPU_DX12_COMPILER') | Out-Null
+    foreach ($k in $case.Env.Keys) { $psi.Environment[$k] = $case.Env[$k] }
+    Write-Host "=== $($case.Name)"
+    $p = [System.Diagnostics.Process]::Start($psi)
+    $stderr = $p.StandardError.ReadToEndAsync()
+    $stdout = $p.StandardOutput.ReadToEndAsync()
+
+    $ok = $false
+    $why = ''
+    try {
+        $client = $null
+        $deadline = (Get-Date).AddSeconds(180)
+        while (-not $client -and (Get-Date) -lt $deadline -and -not $p.HasExited) {
+            try { $client = New-Object System.Net.Sockets.TcpClient('127.0.0.1', $port) } catch { Start-Sleep -Milliseconds 500 }
+        }
+        if (-not $client) { throw "no control channel (exited: $($p.HasExited))" }
+        $client.ReceiveTimeout = 120000
+        $stream = $client.GetStream()
+        $writer = New-Object System.IO.StreamWriter($stream)
+        $writer.AutoFlush = $true
+        $reader = New-Object System.IO.StreamReader($stream)
+        $shot = Join-Path $root 'shot.png'
+        $writer.WriteLine((@{ id = 1; token = $token; method = 'ui.screenshot'; params = @{ path = $shot } } | ConvertTo-Json -Compress))
+        $reply = $reader.ReadLine()
+        Write-Host "screenshot: $reply"
+        if (-not ($reply -like '*"ok":true*') -or -not (Test-Path $shot)) { throw "no frame drawn: $reply" }
+        $writer.WriteLine((@{ id = 2; method = 'app.quit'; params = @{ force = $true } } | ConvertTo-Json -Compress))
+        Write-Host "quit: $($reader.ReadLine())"
+        $client.Close()
+        if (-not $p.WaitForExit(60000)) { throw 'did not exit after app.quit' }
+        if ($p.ExitCode -ne 0) { throw ('exit code 0x{0:x}' -f $p.ExitCode) }
+        $ok = $true
+    } catch {
+        $why = $_.Exception.Message
+    } finally {
+        if (-not $p.HasExited) { $p.Kill(); $p.WaitForExit() }
+    }
+    $err = $stderr.Result
+    Write-Host $err
+    if ($ok -and -not $err.Contains($case.Expect)) { $ok = $false; $why = "stderr does not say '$($case.Expect)'" }
+    $reports = @(Get-ChildItem -Recurse -Filter report.json $crashes -ErrorAction SilentlyContinue)
+    if ($reports.Count -gt 0) {
+        foreach ($r in $reports) { Get-Content $r.FullName | Write-Host }
+        if ($ok) { $ok = $false; $why = 'a crash report was written' }
+    }
+    if ($ok) { Write-Host "PASS: $($case.Name)" } else { Write-Host "FAIL: $($case.Name): $why"; $failed += $case.Name }
+}
+if ($failed.Count -gt 0) { Write-Error ("failed: " + ($failed -join ', ')) }