add more context to exception message (#858)
add more context to exception message (#858)

* add more context to exception message

Signed-off-by: Dirk Thomas <19795c8185177e940eedd30ceb2b716a54a3d5dc@users.noreply.github.com>

* fix linter warnings

Signed-off-by: Dirk Thomas <19795c8185177e940eedd30ceb2b716a54a3d5dc@users.noreply.github.com>

ros2/rclcpp,ros2/rclcpp