RxNodeComponent should set exceptions on the context (#326)

This allows any thrown exceptions to be handled by the runner.

Authors:
  - David Gardner (https://github.com/dagardner-nv)

Approvers:
  - Michael Demoret (https://github.com/mdemoret-nv)

URL: #326

cpp/mrc/include/mrc/node/rx_node.hpp

@@ -234,6 +234,9 @@ class RxNodeComponent : public WritableProvider<InputT>, public WritableAcceptor
                 // Forward to the writable edge
                 this->get_writable_edge()->await_write(std::move(message));
             },
+            [this](std::exception_ptr ptr) {
+                runnable::Context::get_runtime_context().set_exception(std::move(ptr));
+            },
             [this]() {
                 // On completion, release connections
                 WritableAcceptor<OutputT>::release_edge_connection();