fix(serve): use CREATE_NO_WINDOW for the Windows background daemon

.github/workflows/ci.yml

@@ -139,8 +139,22 @@ jobs:
           New-Item -ItemType Directory -Force desktop/src-tauri/binaries | Out-Null
           New-Item -ItemType File -Force "desktop/src-tauri/binaries/agentsview-$hostTriple.exe" | Out-Null
 
+      - name: Fetch Windows desktop Rust dependencies
+        shell: pwsh
+        run: |
+          for ($attempt = 1; $attempt -le 3; $attempt++) {
+            cargo fetch --locked --manifest-path desktop/src-tauri/Cargo.toml
+            if ($LASTEXITCODE -eq 0) {
+              break
+            }
+            if ($attempt -eq 3) {
+              exit $LASTEXITCODE
+            }
+            Start-Sleep -Seconds (10 * $attempt)
+          }
+
       - name: Run Windows desktop update tests
-        run: cargo test --manifest-path desktop/src-tauri/Cargo.toml --lib install_downloaded_update
+        run: cargo test --locked --manifest-path desktop/src-tauri/Cargo.toml --lib install_downloaded_update
 
   coverage:
     runs-on: ubuntu-latest

ci_workflow_test.go

@@ -0,0 +1,61 @@
+package agentsview_test
+
+import (
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gopkg.in/yaml.v3"
+)
+
+type githubWorkflow struct {
+	Jobs map[string]githubWorkflowJob `yaml:"jobs"`
+}
+
+type githubWorkflowJob struct {
+	Steps []githubWorkflowStep `yaml:"steps"`
+}
+
+type githubWorkflowStep struct {
+	Name string `yaml:"name"`
+	Run  string `yaml:"run"`
+}
+
+func TestWindowsDesktopUpdateTestsRetryCargoNetworkFailures(t *testing.T) {
+	contents, err := os.ReadFile(".github/workflows/ci.yml")
+	require.NoError(t, err)
+
+	var workflow githubWorkflow
+	require.NoError(t, yaml.Unmarshal(contents, &workflow))
+
+	job, ok := workflow.Jobs["desktop-windows-unit"]
+	require.True(t, ok, "desktop-windows-unit job must exist")
+
+	fetchIndex, fetchStep := findWorkflowStep(t, job, "Fetch Windows desktop Rust dependencies")
+	testIndex, testStep := findWorkflowStep(t, job, "Run Windows desktop update tests")
+	require.Less(t, fetchIndex, testIndex, "dependencies must be fetched before cargo test")
+
+	assert.Contains(t, fetchStep.Run, "cargo fetch --locked --manifest-path desktop/src-tauri/Cargo.toml")
+	assert.Contains(t, fetchStep.Run, "$attempt")
+	assert.Contains(t, fetchStep.Run, "$LASTEXITCODE")
+	assert.Contains(t, fetchStep.Run, "Start-Sleep")
+	assert.Contains(t, testStep.Run, "cargo test --locked --manifest-path desktop/src-tauri/Cargo.toml --lib install_downloaded_update")
+}
+
+func findWorkflowStep(
+	t *testing.T,
+	job githubWorkflowJob,
+	name string,
+) (int, githubWorkflowStep) {
+	t.Helper()
+
+	for i, step := range job.Steps {
+		if step.Name == name {
+			return i, step
+		}
+	}
+
+	require.Failf(t, "missing workflow step", "step %q was not found", name)
+	return -1, githubWorkflowStep{}
+}

cmd/agentsview/serve_background_windows.go

@@ -9,18 +9,26 @@ import (
 )
 
 const (
-	detachedProcess       = 0x00000008
 	createNewProcessGroup = 0x00000200
+	createNoWindow        = 0x08000000
 )
 
 func configureServeBackgroundCommand(cmd *exec.Cmd) {
+	// Use CREATE_NO_WINDOW rather than DETACHED_PROCESS. A detached
+	// process has no console at all, so every console child it spawns
+	// (notably git, invoked while resolving a session's repo during
+	// sync) forces Windows to allocate a brand-new console window that
+	// flashes on screen. CREATE_NO_WINDOW instead gives the daemon a
+	// hidden console that those children inherit, so they run without
+	// popping a window. CREATE_NEW_PROCESS_GROUP still isolates it from
+	// the launching terminal's Ctrl-C.
 	cmd.SysProcAttr = &syscall.SysProcAttr{
-		CreationFlags: detachedProcess | createNewProcessGroup,
+		CreationFlags: createNoWindow | createNewProcessGroup,
 	}
 }
 
 // terminateProcess stops the server. Windows does not deliver POSIX signals to
-// a detached process, so there is no graceful equivalent of SIGTERM here; the
+// a background process, so there is no graceful equivalent of SIGTERM here; the
 // process is killed and serve stop removes its runtime record afterward.
 func terminateProcess(proc *os.Process) error {
 	return proc.Kill()

cmd/agentsview/serve_background_windows_test.go

@@ -0,0 +1,25 @@
+//go:build windows
+
+package main
+
+import (
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+const testDetachedProcess = 0x00000008
+
+func TestConfigureServeBackgroundCommandUsesHiddenConsole(t *testing.T) {
+	cmd := exec.Command("agentsview", "serve", "--background")
+
+	configureServeBackgroundCommand(cmd)
+
+	require.NotNil(t, cmd.SysProcAttr)
+	flags := cmd.SysProcAttr.CreationFlags
+	assert.NotZero(t, flags&createNoWindow)
+	assert.NotZero(t, flags&createNewProcessGroup)
+	assert.Zero(t, flags&testDetachedProcess)
+}