Issue in building rmf_demo_ws

[prashantking]

I faced two errors while buidling the rmf_demo_ws with colcon build

1. /usr/include/ignition/msgs1/ignition/msgs/color.pb.h:17:2: error: #error This file was generated by an older version of protoc which is
   #error This file was generated by an older version of protoc which is
2. /usr/include/ignition/msgs1/ignition/msgs/world_modify.pb.h:274:93: error: no matching function for call to ‘google::protobuf::internal::ArenaStringPtr::GetNoArena(const string*) const’
   return world_name_.GetNoArena(&::google::protobuf::internal::GetEmptyStringAlreadyInited());

what needs to be done to solve it ? For detailed error info i am attaching logs.
log.txt

[aaronchongth]

This is probably due to an already existing installation of protobuf and its compiler, it looks like this might be a similar issue to this, https://answers.gazebosim.org//question/20101/protobuf-version-error-on-ubuntu-1804-and-gazebo9/

Could you provide some information about your system installation of protobuf?

dpkg -l | grep gazebo9
dpkg -l | grep protobuf

[prashantking]

attaching two log files with the outputs of above commands
gazebo9_info.txt
protobuf_info.txt

dpkg -l | grep gazebo9

ii  gazebo9                   9.12.0-1~bionic                                  amd64        Open Source Robotics Simulator
ii  gazebo9-common            9.12.0-1~bionic                                  all          Open Source Robotics Simulator - Shared files
ii  gazebo9-dbg               9.12.0-1~bionic                                  amd64        Open Source Robotics Simulator - Debugging Symbols
ii  gazebo9-doc               9.12.0-1~bionic                                  all          Open Source Robotics Simulator - Documentation
ii  gazebo9-plugin-base       9.12.0-1~bionic                                  amd64        Open Source Robotics Simulator - base plug-ins
ii  libgazebo9:amd64          9.12.0-1~bionic                                  amd64        Open Source Robotics Simulator - shared library
ii  libgazebo9-dev:amd64      9.12.0-1~bionic                                  amd64        Open Source Robotics Simulator - Development Files

dpkg -l | grep protobuf

ii  libprotobuf-dev:amd64          3.0.0-9.1ubuntu1                    amd64        protocol buffers C++ library (development files)
ii  libprotobuf-lite10:amd64       3.0.0-9.1ubuntu1                    amd64        protocol buffers C++ library (lite version)
ii  libprotobuf10:amd64            3.0.0-9.1ubuntu1                    amd64        protocol buffers C++ library
ii  protobuf-compiler              3.0.0-9.1ubuntu1                    amd64        compiler for protocol buffer definition files
ii  python3-protobuf               3.0.0-9.1ubuntu1                    amd64        Python 3 bindings for protocol buffers

[aaronchongth]

that looks alright to me. did your system already have an installation of gazebo9? or was it installed using the rosdep step mentioned in the documentation?

[prashantking]

I have a default gazebo installation from

sudo apt-get install ros-melodic-desktop-full

other than this i tried google cartographer which shows protobuf from source as 3.4.0.

$ export PATH=/usr/local/bin:$PATH
$ protoc --version
libprotoc 3.4.0

can this create any issue ?

[aaronchongth]

looks like you found the problem, it is also referenced in this issue in the past too.

looks like this might be what you need, https://stackoverflow.com/questions/35896335/how-can-i-uninstall-protobuf-3-0-0

[prashantking]

rmf_demo needs 3.4.0 version or 3.0.0 version of protoc. ?
since cartographer needs 3.4.0 and default is 3.0.0 which one i should remove ?

[Yadunund]

This is an issue that has come up before #21. Gazebo9 requires protobuf 3.0.0 while cartographer installs 3.4.0. Could you try removing 3.4.0 and confirm if that resolves the issue?

[cnboonhan]

Hi, just sneaking in this link which might help.

it is for protobuf 3.0.0 but it hopefully works for removing protobuf 3.4.0, which is what we want

https://stackoverflow.com/questions/35896335/how-can-i-uninstall-protobuf-3-0-0

We should change the protobuf version in that thread to 3.4.0.

[prashantking]

hi, its working now i tried few of the approaches and it worked with this:
go to build directory of protobuf 3.4.0
and then run this command

$ cd build
$ sudo cat install_manifest.txt | sudo xargs rm

and after this when you compile rmf_demo it works fine.
although i doubt that cartographer is going to work after this but that can be solved by building protbuf3.4.0 locally in a workspace.