fix: disable Chromium sandbox for playwright-cli mode in CI containers

pkg/workflow/compiler_main_job_helpers.go

@@ -251,9 +251,22 @@ func (c *Compiler) buildMainJobOutputs(data *WorkflowData) map[string]string {
 func (c *Compiler) buildMainJobEnv(data *WorkflowData) map[string]string {
 	var env map[string]string
 
+	// Disable the Chromium process sandbox for playwright CLI mode.
+	// GitHub Actions runners are containerised environments where kernel namespace
+	// sandboxing is unavailable, which causes playwright-cli to abort with
+	// "Playwright can't run in this sandbox environment".
+	if isPlaywrightCLIMode(data.Tools) {
+		if env == nil {
+			env = make(map[string]string)
+		}
+		env["PLAYWRIGHT_MCP_SANDBOX"] = "false"
+	}
+
 	if data.SafeOutputs != nil {
 		compilerMainJobLog.Printf("Configuring safe-outputs job env for main job (uploadAssets=%v)", data.SafeOutputs.UploadAssets != nil)
-		env = make(map[string]string)
+		if env == nil {
+			env = make(map[string]string)
+		}
 
 		// Set GH_AW_MCP_LOG_DIR for safe outputs MCP server logging
 		// Store in mcp-logs directory so it's included in mcp-logs artifact

pkg/workflow/compiler_main_job_helpers_test.go

@@ -260,6 +260,40 @@ func TestBuildMainJobEnv(t *testing.T) {
 		require.NotNil(t, env)
 		assert.Contains(t, env["GH_AW_PROJECT_UTC"], "+05:30")
 	})
+
+	t.Run("playwright CLI mode sets PLAYWRIGHT_MCP_SANDBOX=false", func(t *testing.T) {
+		c := NewCompiler()
+		c.repoConfigLoaded = true
+		c.repoConfig = &RepoConfig{}
+		data := &WorkflowData{
+			Tools: map[string]any{
+				"playwright": map[string]any{
+					"mode": "cli",
+				},
+			},
+		}
+		env := c.buildMainJobEnv(data)
+		require.NotNil(t, env)
+		assert.Equal(t, "false", env["PLAYWRIGHT_MCP_SANDBOX"])
+	})
+
+	t.Run("safe-outputs with playwright CLI preserves PLAYWRIGHT_MCP_SANDBOX", func(t *testing.T) {
+		c := NewCompiler()
+		c.repoConfigLoaded = true
+		c.repoConfig = &RepoConfig{}
+		data := &WorkflowData{
+			Tools: map[string]any{
+				"playwright": map[string]any{
+					"mode": "cli",
+				},
+			},
+			SafeOutputs: &SafeOutputsConfig{},
+		}
+		env := c.buildMainJobEnv(data)
+		require.NotNil(t, env)
+		assert.Equal(t, "false", env["PLAYWRIGHT_MCP_SANDBOX"])
+		assert.Equal(t, "${{ github.event.repository.default_branch }}", env["DEFAULT_BRANCH"])
+	})
 }
 
 // TestBuildMainJobPermissions tests that permissions are built correctly.

pkg/workflow/playwright_cli_test.go

@@ -20,7 +20,7 @@ func TestGeneratePlaywrightCLIInstallSteps_DefaultVersionUsesCooldown(t *testing
 		},
 	})
 
-	require.Len(t, steps, 2, "expected npm install step plus skills install step")
+	require.Len(t, steps, 2, "expected npm install step and skills install step")
 
 	installStep := strings.Join(steps[0], "\n")
 	assert.Contains(t, installStep, "npm install -g @playwright/cli@"+string(constants.DefaultPlaywrightCLIVersion))

pkg/workflow/testdata/TestWasmGolden_CompileFixtures/playwright-cli-mode.golden

@@ -337,6 +337,7 @@ jobs:
     env:
       GH_AW_RUNTIME_FEATURES: ${{ vars.GH_AW_RUNTIME_FEATURES }}
       GH_AW_WORKFLOW_ID_SANITIZED: playwrightclimode
+      PLAYWRIGHT_MCP_SANDBOX: false
     outputs:
       agentic_engine_timeout: ${{ steps.detect-agent-errors.outputs.agentic_engine_timeout || 'false' }}
       ai_credits_rate_limit_error: ${{ steps.parse-mcp-gateway.outputs.ai_credits_rate_limit_error || 'false' }}

pkg/workflow/testdata/wasm_golden/WasmBinary/playwright-cli-mode.golden

@@ -337,6 +337,7 @@ jobs:
     env:
       GH_AW_RUNTIME_FEATURES: ${{ vars.GH_AW_RUNTIME_FEATURES }}
       GH_AW_WORKFLOW_ID_SANITIZED: playwrightclimode
+      PLAYWRIGHT_MCP_SANDBOX: false
     outputs:
       agentic_engine_timeout: ${{ steps.detect-agent-errors.outputs.agentic_engine_timeout || 'false' }}
       ai_credits_rate_limit_error: ${{ steps.parse-mcp-gateway.outputs.ai_credits_rate_limit_error || 'false' }}