Default ROS_HOME and ROS_LOG_DIR env vars in ros2_cpp_test to TEST_UN…

…DECLARED_OUTPUTS_DIR

ros2/cc_defs.bzl

@@ -124,4 +124,7 @@ def ros2_cpp_test(name, ros2_package_name = None, set_up_ament = False, **kwargs
         set_up_ament: If true, sets up ament file tree for the test target.
         **kwargs: https://bazel.build/reference/be/common-definitions#common-attributes-tests
     """
-    _ros2_cpp_exec(cc_test, name, ros2_package_name, set_up_ament, **kwargs)
+    env = kwargs.pop("env", {})
+    env["ROS_HOME"] = env.get("ROS_HOME", "$TEST_UNDECLARED_OUTPUTS_DIR")
+    env["ROS_LOG_DIR"] = env.get("ROS_LOG_DIR", "$TEST_UNDECLARED_OUTPUTS_DIR")
+    _ros2_cpp_exec(cc_test, name, ros2_package_name, set_up_ament, env = env, **kwargs)

ros2/test/BUILD.bazel

@@ -6,6 +6,7 @@ load(
     "py_ros2_interface_library",
     "ros2_interface_library",
 )
+load("@com_github_mvukov_rules_ros2//ros2:cc_defs.bzl", "ros2_cpp_test")
 load("@rules_python//python:defs.bzl", "py_test")
 
 py_test(
@@ -45,3 +46,10 @@ py_test(
         ":py_test_action",
     ],
 )
+
+ros2_cpp_test(
+    name = "test_rclcpp",
+    size = "small",
+    srcs = ["test_rclcpp.cpp"],
+    deps = ["@ros2_rclcpp//:rclcpp"],
+)

ros2/test/test_rclcpp.cpp

@@ -0,0 +1,9 @@
+#include <rclcpp/rclcpp.hpp>
+
+int main(int argc, char** argv) {
+  // If neither $ROS_HOME nor $ROS_LOG_DIR are set to a valid directory, rclcpp:init() will fail with errors
+  // 'rcutils_expand_user failed, at external/ros2_rcl_logging/rcl_logging_interface/src/logging_dir.c:81'
+  // 'Failed to get logging directory, at external/ros2_rcl_logging/rcl_logging_spdlog/src/rcl_logging_spdlog.cpp:83'
+  rclcpp::init(argc, argv);
+  return 0;
+}