fix(desktop): preserve WSL runtime installation errors

apps/desktop/src/backend/DesktopBackendConfiguration.test.ts

@@ -551,6 +551,7 @@ describe("DesktopBackendConfiguration", () => {
         archiveHash: "b".repeat(64),
         wsl: () => ({
           prepareRuntime: () => ({ ok: false, reason: "archive is corrupt" }),
+          invalidateRuntime: () => Effect.die("failed staging must not invalidate a runtime"),
           ensureNodePty: (_distro, root) => {
             observedNodePtyRoots.push(root);
             return { ok: true, nodePath: "/usr/bin/node", resolvedPath: "/usr/bin:/bin" };
@@ -615,6 +616,35 @@ describe("DesktopBackendConfiguration", () => {
     );
   });
 
+  it.effect("resolveWsl preserves the staging error when the mounted fallback is fatal", () =>
+    withPackagedWslHarness(
+      {
+        archiveHash: "b".repeat(64),
+        wsl: () => ({
+          prepareRuntime: () => ({
+            ok: false,
+            reason:
+              "t3: error while loading shared libraries: libatomic.so.1: cannot open shared object file",
+          }),
+          ensureNodePty: () => ({
+            ok: false,
+            reason: "the packaged Linux node-pty binary was not included",
+            fatal: true,
+          }),
+        }),
+      },
+      () =>
+        Effect.gen(function* () {
+          const configuration = yield* DesktopBackendConfiguration.DesktopBackendConfiguration;
+          const config = yield* configuration.resolveWsl({ port: 5000, distro: "Ubuntu" });
+          const failure = Option.getOrThrow(config.preflightFailure);
+
+          assert.isTrue(failure.fatal);
+          assert.include(failure.reason, "libatomic.so.1");
+        }),
+    ),
+  );
+
   it.effect("resolveWsl keeps the staged runtime when the mounted tree fails too", () => {
     const stagedAppRoot = "/home/test/.t3/wsl-runtime/cache";
     const invalidatedRuntimeIds: string[] = [];

apps/desktop/src/backend/DesktopBackendConfiguration.ts

@@ -386,7 +386,7 @@ const runWslPreflight = Effect.fn("desktop.backendConfiguration.wslPreflight")(f
       : ({ ok: true, windowsEntryPath, linuxAppRoot: mountedAppRoot.value } as const);
   });
 
-  let stagedFailure: { readonly runtimeId: string; readonly reason: string } | undefined;
+  let stagedFailure: { readonly runtimeId?: string; readonly reason: string } | undefined;
   const failedStaged = (failure: { readonly reason: string }) =>
     ({
       _tag: "Failed",
@@ -417,6 +417,7 @@ const runWslPreflight = Effect.fn("desktop.backendConfiguration.wslPreflight")(f
       );
       stagedFailure = { runtimeId: input.runtimeArchive.runtimeId, reason: stagedProbe.reason };
     } else {
+      stagedFailure = { reason: runtime.reason };
       yield* Effect.logWarning(
         "Could not stage the WSL runtime; launching from the mounted server tree instead.",
         { reason: runtime.reason },
@@ -446,7 +447,7 @@ const runWslPreflight = Effect.fn("desktop.backendConfiguration.wslPreflight")(f
       : failedNodePty(nodePtyResult);
   }
 
-  if (stagedFailure) {
+  if (stagedFailure?.runtimeId) {
     yield* wslEnv.invalidateRuntime(runningDistro, stagedFailure.runtimeId);
   }
 

apps/desktop/src/wsl/DesktopWslEnvironment.test.ts

@@ -182,7 +182,7 @@ describe("WSL runtime cache", () => {
 
     expect(script).toContain('runtime_parent="$HOME/.t3/wsl-runtime"');
     expect(script).toContain('  [ -f "$ready_marker" ] &&');
-    expect(script).toContain('    runtime_entry_runs "$runtime_root" &&');
+    expect(script).toContain('    runtime_entry_runs "$runtime_root" 2>/dev/null &&');
     expect(script).toContain("if runtime_is_ready; then");
     expect(script).not.toContain("bin.mjs");
     expect(script).not.toContain("node-pty");
@@ -262,7 +262,7 @@ describe("WSL runtime cache", () => {
       "b".repeat(64),
     );
 
-    expect(script).toContain('  [ -x "$1/t3" ] && "$1/t3" --version >/dev/null 2>&1');
+    expect(script).toContain('  [ -x "$1/t3" ] && "$1/t3" --version >/dev/null');
 
     const entryCheckDefined = script.indexOf("runtime_entry_runs() {");
     const readinessDefined = script.indexOf("runtime_is_ready() {");
@@ -374,14 +374,14 @@ describe.skipIf(posixShellRunner === null)("WSL runtime install script (executed
     fixtures.length = 0;
   });
 
-  const createFixture = () => {
+  const createFixture = (serverEntry = SERVER_ENTRY_SOURCE) => {
     const result = runShell(
       [
         "set -eu",
         "work=$(mktemp -d)",
         'stage="$work/stage/t3-0.0.0-linux-x64"',
         'mkdir -p "$stage/node_modules/node-pty/build/Release" "$work/home"',
-        `printf '%s' ${sh(SERVER_ENTRY_SOURCE)} > "$stage/t3"`,
+        `printf '%s' ${sh(serverEntry)} > "$stage/t3"`,
         'chmod +x "$stage/t3"',
         `printf '%s' 'pty-native-payload' > "$stage/node_modules/node-pty/build/Release/pty.node"`,
         `tar -czf "$work/wsl-runtime.tar.gz" -C "$work/stage" t3-0.0.0-linux-x64`,
@@ -495,6 +495,18 @@ describe.skipIf(posixShellRunner === null)("WSL runtime install script (executed
     expect(parseWslRuntimeRoot(warm.stdout)).toBe(fixture.runtimeRoot);
   });
 
+  it("retains the loader error when a bundled executable needs a missing system library", () => {
+    const fixture = createFixture(
+      '#!/bin/sh\nprintf "error while loading shared libraries: libatomic.so.1: cannot open shared object file\\n" >&2\nexit 127\n',
+    );
+
+    const result = fixture.install();
+
+    expect(result.status).not.toBe(0);
+    expect(result.stderr).toContain("libatomic.so.1");
+    expect(parseWslRuntimeRoot(result.stdout)).toBeNull();
+  });
+
   it("reinstalls a cache whose executable was truncated", () => {
     const fixture = createFixture();
     expect(fixture.install().status).toBe(0);

apps/desktop/src/wsl/DesktopWslEnvironment.ts

@@ -274,7 +274,7 @@ export const buildWslRuntimeInstallScript = (
     `runtime_root="$runtime_parent/${safeRuntimeId}"`,
     `ready_marker="$runtime_root/${WSL_RUNTIME_READY_MARKER}"`,
     "runtime_entry_runs() {",
-    '  [ -x "$1/t3" ] && "$1/t3" --version >/dev/null 2>&1',
+    '  [ -x "$1/t3" ] && "$1/t3" --version >/dev/null',
     "}",
     // Hashing the entry is what tells a working cache from one whose `t3` was
     // swapped or half-written after install: the file is still there and may
@@ -285,7 +285,7 @@ export const buildWslRuntimeInstallScript = (
     "}",
     "runtime_is_ready() {",
     '  [ -f "$ready_marker" ] &&',
-    '    runtime_entry_runs "$runtime_root" &&',
+    '    runtime_entry_runs "$runtime_root" 2>/dev/null &&',
     `    recorded_entry_digest=$(tr -d '[:space:]' < "$ready_marker" 2>/dev/null) &&`,
     '    [ -n "$recorded_entry_digest" ] &&',
     '    [ "$recorded_entry_digest" = "$(runtime_server_entry_digest "$runtime_root")" ]',