Bug#966378: gazebo: exits with code 255 attempting to create a joint in model

[ydirson at free.fr]

Package: gazebo
Version: 11.0.0+dfsg1-4+b3

context: after reading the "beginner:model editor" tutorial while on the move,
I tried to reproduce it from memory: creation of links, but manual positionning
of wheels and then creation of joints.

Then getting back to the tuto I wanted to try the "align links" feature, so I
cancelled my joint creations and some wheel positionning with "undo", moved a
wheel some more manually.

Then I clicked the "create joint" button and the UI bombed out, with this in the
terminal:

$ gazebo
Node::Advertise(): Error advertising topic [/ground_plane/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone_1/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone_1/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone_1/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]. Did you forget to start the discovery service?
Node::Advertise(): Error advertising topic [/ModelPreview_0/link_3/joint_cmd]. Did you forget to start the discovery service?
$ echo $?
255
$

The only non-trivial information Icould find in logs is:

$ cat .gazebo/client-11345/default.log
Gazebo multi-robot simulator, version 11.0.0
Copyright (C) 2012 Open Source Robotics Foundation.
Released under the Apache 2 License.
http://gazebosim.org


(1595859321 302209616) [Msg] Waiting for master.
(1595859321 313861858) [Msg] Connected to gazebo master @ http://127.0.0.1:11345
(1595859321 313892719) [Msg] Publicized address: 10.100.0.1
(1595859321 315079664) [Wrn] [GuiIface.cc:297] Couldn't locate specified .ini. Creating file at "/home/yann/.gazebo/gui.ini"
(1595859321 315166142) Loaded .ini file from: "/home/yann/.gazebo/gui.ini"
(1595859322 504761214) [Wrn] [ModelDatabase.cc:212] Unable to connect to model database using [http://models.gazebosim.org//database.config]. Only locally installed models will be available.
(1595859323 371021704) No spacenav daemon found. Spacenav functionality is disabled
(1595859350 124401526) [Wrn] [Publisher.cc:136] Queue limit reached for topic /gazebo/default/user_camera/pose, deleting message. This warning is printed only once.
(1595859858 594394295) [Wrn] [ModelCreator.cc:2948] Couldn't find top level visual for [ModelPreview_0::link_0]. Not selecting in 3D scene.
(1595859862 562385788) [Wrn] [ModelCreator.cc:2948] Couldn't find top level visual for [ModelPreview_0::link_0]. Not selecting in 3D scene.
(1595860378 375175810) [Err] [JointControlWidget.cc:393] Error advertising topic [/ground_plane/joint_cmd]
(1595860423 124412332) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]
(1595860461 619782521) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3/joint_cmd]
(1595860473 15299013) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]
(1595860482 492269163) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone_1/joint_cmd]
(1595860504 878776990) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]
(1595860507 364929069) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]
(1595860512 358209615) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]
(1595860532 480516675) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]
(1595860537 803114798) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone_0/joint_cmd]
(1595860559 177641078) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone_1/joint_cmd]
(1595860753 122460883) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone_1/joint_cmd]
(1595860793 835628746) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3_clone/joint_cmd]
(1595860866 534162486) [Err] [JointControlWidget.cc:393] Error advertising topic [/ModelPreview_0/link_3/joint_cmd]