Gate MXC E2E on GitHub Actions

docs/WINDOWS_NODE_TESTING.md

@@ -132,6 +132,7 @@ When the node connects, it advertises these capabilities:
 ### Full Gateway `system.run` MXC runtime proof
 - The focused E2E below provisions a fresh WSL Gateway, starts an isolated tray instance, sets a local exec approval rule through MCP, invokes `system.run` through the real Gateway `node.invoke` path, and verifies tray MXC diagnostics show contained `mxc-direct-appc` execution for both allowed execution and denied writes to the tray data directory.
 - Run it when validating the Gateway/Windows node runtime path, not just direct MCP or shared library behavior.
+- GitHub-hosted Actions runners do not provide a working MXC/AppContainer runtime. The regular cloud E2E matrix should report these MXC proofs as skipped while still running the rest of setup-connect. Run the proof on a local MXC-enabled Windows machine. Only set `OPENCLAW_RUN_MXC_E2E=1` in GitHub Actions when using an MXC-enabled self-hosted runner.
 - When reproducing this manually against an existing Gateway, make sure `gateway.nodes.allowCommands` includes `system.run`, `system.run.prepare`, and `system.which`, then approve any `pending-reapproval` request with `openclaw nodes approve <pendingRequestId>`. The node can advertise `system.run` while the Gateway still blocks it until both gates are updated.
 
   ```powershell

tests/OpenClaw.E2ETests/E2EFactAttribute.cs

@@ -31,6 +31,8 @@ public MxcE2EFactAttribute()
 
 internal static class MxcE2ETestGate
 {
+    private const string GitHubActionsEnvVar = "GITHUB_ACTIONS";
+    private const string ExplicitGitHubActionsOptInEnvVar = "OPENCLAW_RUN_MXC_E2E";
     private static readonly Lazy<string?> s_skipReason = new(GetSkipReason);
 
     public static string? SkipReason => s_skipReason.Value;
@@ -40,6 +42,12 @@ internal static class MxcE2ETestGate
         if (!E2ETestGate.IsEnabled)
             return $"E2E tests disabled. Set {E2ETestGate.EnvVar}=1 to enable.";
 
+        if (IsEnabled(GitHubActionsEnvVar) && !IsEnabled(ExplicitGitHubActionsOptInEnvVar))
+        {
+            return "MXC E2E test skipped in GitHub Actions because hosted runners do not provide a working MXC/AppContainer runtime. " +
+                $"Run on a local MXC-enabled Windows machine, or set {ExplicitGitHubActionsOptInEnvVar}=1 only on an MXC-enabled self-hosted runner.";
+        }
+
         try
         {
             var availability = ProbeAvailabilityForE2E();
@@ -167,6 +175,11 @@ private static bool FileExists(string? path)
         catch { return false; }
     }
 
+    private static bool IsEnabled(string envVar) =>
+        Environment.GetEnvironmentVariable(envVar) is { } value &&
+        (string.Equals(value, "1", StringComparison.OrdinalIgnoreCase) ||
+         string.Equals(value, "true", StringComparison.OrdinalIgnoreCase));
+
     private static string GetSdkArchString() => System.Runtime.InteropServices.RuntimeInformation.OSArchitecture switch
     {
         System.Runtime.InteropServices.Architecture.Arm64 => "arm64",