Small improvements to the error output in component parser to make de…

…bugging easier. (#1580)

* Small improvements to the error output in component parser to make debugging easier.

* Correct formatting.

hardware_interface/src/component_parser.cpp

@@ -797,11 +797,13 @@ std::vector<HardwareInfo> parse_control_resources_from_urdf(const std::string &
  tinyxml2::XMLDocument doc;
  if (!doc.Parse(urdf.c_str()) && doc.Error())
  {
- throw std::runtime_error("invalid URDF passed in to robot parser");
+ throw std::runtime_error(
+ "invalid URDF passed in to robot parser: " + std::string(doc.ErrorStr()));
  }
  if (doc.Error())
  {
- throw std::runtime_error("invalid URDF passed in to robot parser");
+ throw std::runtime_error(
+ "invalid URDF passed in to robot parser: " + std::string(doc.ErrorStr()));
  }
 
  // Find robot tag
@@ -875,7 +877,7 @@ std::vector<HardwareInfo> parse_control_resources_from_urdf(const std::string &
  auto urdf_joint = model.getJoint(joint.name);
  if (!urdf_joint)
  {
- throw std::runtime_error("Joint " + joint.name + " not found in URDF");
+ throw std::runtime_error("Joint '" + joint.name + "' not found in URDF");
  }
  if (!urdf_joint->mimic && joint.is_mimic == MimicAttribute::TRUE)
  {