Disable brittle tests

Author: lionel-

crates/ark/tests/kernel.rs

@@ -1192,10 +1192,16 @@ fn test_shutdown_request_with_restart() {
     DummyArkFrontend::wait_for_cleanup();
 }
 
+static SHUTDOWN_TESTS_ENABLED: bool = false;
+
 // Can shut down Ark when running a nested debug console
 // https://github.com/posit-dev/positron/issues/6553
 #[test]
 fn test_shutdown_request_browser() {
+    if !SHUTDOWN_TESTS_ENABLED {
+        return;
+    }
+
     install_sigint_handler();
     let frontend = DummyArkFrontend::lock();
 
@@ -1217,6 +1223,9 @@ fn test_shutdown_request_browser() {
     frontend.send_shutdown_request(true);
     frontend.recv_iopub_busy();
 
+    // There is a race condition between the Control thread and the Shell
+    // threads. Ideally we'd wait for both the Shutdown reply and the IOPub Idle
+    // messages concurrently instead of sequentially.
     let reply = frontend.recv_control_shutdown_reply();
     assert_eq!(reply.status, Status::Ok);
     assert_eq!(reply.restart, true);
@@ -1228,6 +1237,10 @@ fn test_shutdown_request_browser() {
 
 #[test]
 fn test_shutdown_request_while_busy() {
+    if !SHUTDOWN_TESTS_ENABLED {
+        return;
+    }
+
     install_sigint_handler();
     let frontend = DummyArkFrontend::lock();
 
@@ -1245,6 +1258,7 @@ fn test_shutdown_request_while_busy() {
     assert_eq!(reply.status, Status::Ok);
     assert_eq!(reply.restart, false);
 
+    // It seems this isn't emitted on older R versions
     frontend.recv_iopub_stream_stderr("\n");
     frontend.recv_iopub_idle();