Currently, multiple un-labeled collisions in a single link produces following errors, e.g.
SDF has no <sdf> element in file[/home/hsu/local/share/drcsim-1.4/gazebo_models/atlas_description/atlas_sandia_hands/atlas_sandia_hands.urdf]
Warning: 'default' collision group has 2 collisions for Link 'l_clav', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'l_farm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'l_hand', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'l_larm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'l_lglut', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'l_scap', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'l_talus', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'l_uarm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'l_uglut', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'mtorso', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'pelvis', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'r_clav', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'r_farm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'r_hand', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'r_larm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'r_lglut', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'r_scap', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'r_talus', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'r_uarm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'r_uglut', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 3 collisions for Link 'utorso', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 7 collisions for Link 'right_palm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f0_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f0_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f1_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f1_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f2_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f2_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f3_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'right_f3_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 7 collisions for Link 'left_palm', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f0_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f0_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f1_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f1_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f2_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f2_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f3_0', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'left_f3_2', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'head', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
Warning: 'default' collision group has 2 collisions for Link 'hokuyo_link', taking the first one as default
at line 546 in /tmp/buildd/ros-groovy-urdfdom-0.2.7-0precise-20130118-0054/urdf_parser/src/link.cpp
consider muting the warnings or add group names to links in urdf.
Original report (archived issue) by John Hsu (Bitbucket: hsu, GitHub: hsu).
Currently, multiple un-labeled collisions in a single link produces following errors, e.g.
consider muting the warnings or add group names to links in urdf.