Follow-up from #166. We currently have Python tutorials, but there are only place-holder pages for the C++ tutorials.

Similar to the existing Python tutorials, the code can live in the action_tutorials package. To avoid maintaining multiple copies of the tutorial code, we might consider moving the entire tutorial into the action_tutorials package and reference it from the ROS 2 documentation.

Thanks for the detailed install instructions, it is appreciated.

At the very last step, when I try to run the example talker, I get the following error:

I'm not aware of any existing resource about the changes for parameters going from ROS 1 to ROS 2. In particular, I think it would be useful if there was at least a brief about how to update existing parameter YAML files to be ROS 2 compatible. Perhaps as part of the Migration Guide. I don't know the details of the necessary changes, but I believe there are some.

I have followed https://index.ros.org/doc/ros2/Installation/Crystal/Linux-Install-Debians/ to install ros2, but can't install rqt and turtlesim, anything have I missed?
~$ sudo apt install ros-ardent-turtlesim
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package ros-ardent-turtlesim

In section at
https://index.ros.org/doc/ros2/Tutorials/Logging-and-logger-configuration/#using-the-logger-config-component

The command
ros2 run composition api_composition
returns the error text
No executable found

This is with ros2 install from
https://ci.ros2.org/view/packaging/job/packaging_linux-aarch64/

and with setup.bash sourced.

Follow up from ros2/ros2#583.

With Actions now available in rclcpp and rclpy and the upcoming CLI tool (ros2/ros2cli#202), we can write some user-friendly tutorials. Looking at the acitonlib tutorials from ROS 1 for inspiration, here is a list of proposed tutorials:

• Creating a new Action
  • Walk through specifying and building a new action type.
• Writing an Action Server (C++)
  • Walk through an example of writing a Fibonacci action server as a composable class.
• Writing an Action Client (C++)
  • Walk through an example of writing a Fibonacci action client as a composable class.
• Writing an Action Server (Python)
• Writing an Action Client (Python)
• Action CLI tool
  • Sending a goal to an action server with the CLI tool.
  • How to introspect actions in a ROS system with the CLI tool.

This page has some detailed information about the QoS settings that existed up through Crystal, but doesn't document the new settings.

https://index.ros.org/doc/ros2/Concepts/About-Quality-of-Service-Settings

@ros2/aws-robotics

I was following the tutorial for the Python Action Server here: https://index.ros.org/doc/ros2/Tutorials/Actions/Writing-an-Action-Server-Python/

One problem that I see with it is that it is a bit hard to follow. Particularly, it isn't easy to see that each code snippet augments the last one and isn't a complete cut-n-pastable example on its own. I think it would be better if we restructured it so that either:

1. Each example was a copy-n-pastable example, or
2. Each section built on the last somehow (maybe by putting the main in separate file?)

In this paragraph, the link RMW package for RTI Connext points to a nonexistent URL.
I suspect it might point to this one.
If you guys could confirm that I can send a small PR with the fix.
Thanks!

While the current troubleshooting page does get people on the right track, it does not directly provide solutions to addressing certain issues such as multicasting. Moreover, it is not really visible to new users (aside from the sidebar...).

My suggestion is to:

1. Add the pub/sub demo to the Debian installation instructions page (since they are only on the building from source instructions).
2. Add a link to Troubleshooting on the Debian install instructions page.
3. Update the Troubleshooting page with instructions on how to fix the multicasting issue:
   1. Check ifconfig and see if the MULTICAST flag is set for lo:
   2. If not, allow UDP multicast with ufw

      sudo ufw allow in proto udp to 224.0.0.0/4
      sudo ufw allow in proto udp from 224.0.0.0/4

@maryaB-osr @wjwwood if this sounds good, I will open a PR for this.

The ROS 2 tutorial prerequisites say that users should follow the instructions for a binary installation. However, the Understanding Services section of the tutorial uses command line introspection tools like find and type that aren't included in any of the binary distributions. This has caused confusion for some people working through this tutorial (see here and here).

There should probably be a caveat about version compatibility in the section introducing these commands.

https://index.ros.org/doc/ros2/Features/
has a linkt to
https://github.com/ros2/ros1_bridge/blob/master/README
which gives me 404

Refiling from @tobiasblass ros-infrastructure/rosindex#131

At https://index.ros.org/doc/ros2/Logging-and-logger-configuration/#console-output-formatting
The link "the RCUTILS_CONSOLE_OUTPUT_FORMAT environment variable" does not exist.

It's now here: https://github.com/ros2/ros2_documentation/blob/master/source/Tutorials/Logging-and-logger-configuration.rst I couldn't find the intended target quickly.

The Windows documentation suggests to install Qt 5.10.0, however, this will not be listed by the Qt installer, see below

We see messages "This recording has been archived" where the recordings should appear.

https://index.ros.org/doc/ros2/Tutorials/Managed-Nodes/

Hi,
I was following the ros2 crystal install from source instructions.

I'm using a Docker image for Ubuntu 18.04

FROM ubuntu:18.04

# working directory
ENV HOME /root
WORKDIR $HOME

# Set timezone otherwise tz will ask for it
ENV TZ=America/Los_Angeles
RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone

# general utilities
RUN apt-get update && apt-get install -y \
    curl \
    wget \
    git \
    vim \
    nano \
    python3-pip

# pip
RUN pip3 install --upgrade pip

# Locale options
RUN apt-get install -y locales

This is the initial content of the Dockerfile, then I added all the instructions found here.
You find the full Dockerfile here

Even if I'm on Ubuntu 18.04, I need the following lines

RUN python3 -m pip install -U \
  pytest \
  pytest-cov \
  pytest-runner \
  setuptools

Otherwise a lots of warnings are prompted about the correct version of pytest not being found and then the build fails while building the demo_nodes_cpp package.

This warning appears for several packages

CMake Warning at /root/ros2_ws/install/ament_cmake_pytest/share/ament_cmake_pytest/cmake/ament_add_pytest_test.cmake:73 (message):
The Python module 'pytest' was not found, pytests can not be run (e.g. on
Ubuntu/Debian install the package 'python3-pytest')
Call Stack (most recent call first):
CMakeLists.txt:31 (ament_add_pytest_test)

The error for the demo_nodes_cpp package

CMake Error at CMakeLists.txt:114 (set_property):
set_property given TEST names that do not exist:

test_tutorial_add_two_ints_server_add_two_ints_client_async__rmw_opensplice_cpp

Call Stack (most recent call first):
/root/ros2_ws/build/demo_nodes_cpp/call_for_each_rmw_implementation.cmake:1 (tests)
/root/ros2_ws/install/rmw_implementation_cmake/share/rmw_implementation_cmake/cmake/call_for_each_rmw_implementation.cmake:64 (include)
CMakeLists.txt:121 (call_for_each_rmw_implementation)

I'd like to attach a shell script to set up robotics development environment with kinds of software components on develop machine. But not sure if it's an acceptable way to attach the shell script in this project, so my document can refer to that directly.

On Quality Of Service page, under the 'Command line options' title. The following options are missing:

• From showimage:
• --f: Publish frequency in Hz. 30 (default)
• --t TOPIC: use topic TOPIC instead of the default
• From cam2image:
• -b: produce images of burgers rather than connecting to a camera
• -t TOPIC: use topic TOPIC instead of the default
• -f: Publish frequency in Hz. 30 (default)

Following ros2/rclcpp#665 (and ros2/demos#319), the composition tutorial needs to be updated. For example, api_composition is no longer a valid executable.

It would be nice to explain some of the issues presented about using parameters in a launch file here.

Specifically:

• How to write a config/parameters file.
• How to install the file in a cmake/python based package.
• How to load the file in your launch description/node.
• Things like how order of the parameters matter (specifically this comment)
• How to read the parameters in a node.
• Feature gaps (the composable node issue in the link above)

Not sure where this should live, but I think Understanding ROS 2 parameters, Launching/monitoring multiple nodes with Launch, or a new tutorial in the developers section would be good.

In #359 (comment) , we discussed the fact that it would be nice to have a ROS 2 tutorial talking about rosdep in more detail. This issue tracks the addition of that tutorial to ros2_documentation.

It should probably talk about:

• What rosdep is
• It's relationship to the package.xml
• The kinds of keys that rosdep will work with (ROS distribution keys, package keys, pip keys)
• How to use rosdep on the command-line
• How to submit new keys to rosdistro (or at least point to other documentation that describes that)

Feature request

Instructions for installing ros2-base from source.

Feature description

Documentation with a list of the essential packages for each distribution. This would allow a user to install precisely the packages they want, from source, by ignoring all auxiliary packages. This is important, because currently installing from source requires many gigabytes, but not all ros2 packages are used by everyone.

Implementation considerations

Alternatively, instructions for how to compile additional packages with new or modified code on top of an existing debian package installation.

I just installed Bouncy on 18.04 using the (debian) guide (https://index.ros.org/doc/ros2/Linux-Install-Debians/) and It looks like I was missing important libraries (like colcon). I didn't take the time to figure out what was missing, I just ran apt install on all the libraries listed under the build from source section. I believe this either a documentation bug or the debs should rely on and pull in the missing libraries.

I tried compiling rosbag2 by pulling latest ros2 ws. rosbag2 uses yaml_cpp_vendor whereas ros2_ws "ros2.repos" doesnt include it. It still has rviz_yaml_cpp_vendor. Can someone please update it

Next to the git repo description there is a box for a webpage link. Add https://index.ros.org/doc/ros2/

Currently this is not well documented on the README

For a new user on a new system it cannot be assumed that they have rosdep installed if you look through our direct prerequisites. A short term fix here would be to add it to somewhere explicitly. However I think that it might make sense for us to have an development environment setup tutorial that we can reference as a prerequisite.

Based on ros2/ci#246

I am not sure if this is the right place to open this issue. Please refer to the right place in case it's not here.

I am currently unable to display readme files on the rosindex. The page shows an error message:

lifecycle/README.rst
Could not convert RST to MD: No such file or directory - pandoc

 CHANGELOG
Could not convert RST to MD: No such file or directory - pandoc

For example, see here: https://index.ros.org/p/lifecycle/github-ros2-demos/#dashing

First off: These docs are awesome! Thank you!

In crawling around to tinker with Bazel stuff (using company acct, @EricCousineau-TRI), I initially missed these docs.
I knew a little bit about index.ros.org/docs/ros2, but, uh, hadn't looked deeply enough here.

One thing that would have motivated me to more closely read the docs would have been links from the code repositories back to one of the forms of documentation (either docs.ros.org or index.ros.org/docs), and possibly the package's docs on index.ros.org.

Examples (at current SHA1s):
https://github.com/ros2/rclcpp/tree/0a44344f4332f3a8818291dc46c5491192b41c78 - No README / overview?
https://github.com/ros2/rclpy/tree/28a77736f1d5ffd13a1dc065e066fab3a89f27f2 - README, but no link to docs?
https://github.com/ros2/rmw/tree/0d7db0fee279a226285e63a594c5448ef4815c57 - No README
https://github.com/ros2/rmw_implementation/tree/7c2f2c8956a58c085602aca6a5cf82a21e2c6089 - No README

If it would help, I'd be more than happy to take a stab at adding this information to one of these packages as a PR, then making the parallel PRs (which could possibly trigger an update for the package description?).

EDIT(2020/05/30): Have not yet had a chance to delve into this :(

I'm attempting to following this example with a NVIDIA Jetson Nano and have run into an error that I can not clear. It looks like it is looking for a .cmake file for test_msgs but it can not find one an I was not able to locate it either.
I'm following the install instructions from:
https://index.ros.org/doc/ros2/Installation/Crystal/Linux-Install-Binary/

This is the error from running "colcon build --symlink-install"

Starting >>> rcl_interfaces
Finished <<< unique_identifier_msgs [13.4s]   
Starting >>> std_msgs
Finished <<< rcl_interfaces [17.6s]                                            
Starting >>> rcl                                           
--- stderr: rcl                                                              
CMake Error at test/CMakeLists.txt:4 (find_package):
  By not providing "Findtest_msgs.cmake" in CMAKE_MODULE_PATH this project
  has asked CMake to find a package configuration file provided by
  "test_msgs", but CMake did not find one.

  Could not find a package configuration file provided by "test_msgs" with
  any of the following names:

    test_msgsConfig.cmake
    test_msgs-config.cmake

  Add the installation prefix of "test_msgs" to CMAKE_PREFIX_PATH or set
  "test_msgs_DIR" to a directory containing one of the above files.  If
  "test_msgs" provides a separate development package or SDK, be sure it has
  been installed.

---
Failed   <<< rcl	[ Exited with code 1 ]
Aborted  <<< std_msgs                                                    

Summary: 94 packages finished [4min 39s]
  1 package failed: rcl
  1 package aborted: std_msgs
  1 package had stderr output: rcl
  79 packages not processed

In ros2_documentation/source/Installation/Crystal/Linux-Install-Binary.rst it says to install python-rosdep and run rosdep init. My system tells me it is already initialized, presumably because I have kinetic already installed. Should I simply ignore the warning and move on?

I'm not merely asking for help, but wondering if there should be an additional instruction on that page to ignore the warning about it being already initialized?

My CI started failing a few days ago with the following types of errors (not just for rosidl_adapter).

Finished <<< opensplice_cmake_module [4.29s]
stderr: rosidl_adapter‌
CMake Warning at /root/ros2_ws/ros2_base/install/share/ament_cmake_pytest/cmake/ament_add_pytest_test.cmake:73 (message):
  The Python module 'pytest' was not found, pytests can not be run (e.g.  on
  Ubuntu/Debian install the package 'python3-pytest')
Call Stack (most recent call first):
  CMakeLists.txt:31 (ament_add_pytest_test)

After some troubleshooting this seems to be due to the fact that when pytest is installed through pip, it installs version 4.6.1 which seems to clobber some of the other ROS python dependencies.

When this version is installed and I run: python3 -m pytest --version, it fails with a dist error.

If i remove the pip version everything works ok:

RUN python3 -m pip uninstall pytest -y

I think the build directions should be updated with a workaround for this issue: https://index.ros.org/doc/ros2/Installation/Dashing/Linux-Development-Setup/

General install instructions for people who don't use any of the listed platforms.
I'd appreciate some notes on the technical steps, or discussion on the best way to do this or if it's relevant.

When installing ROS2 (Building ROS 2 on Linux) on a NVIDIA Jetson Nano running Ubuntu 18, I am seeing the following error when running the "Install dependencies using rosdep"

Ubuntu Version

lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 18.04.2 LTS
Release:	18.04
Codename:	bionic

These are the steps I ran to see the issue

sudo rosdep init
rosdep update
# [Ubuntu 18.04]
rosdep install --from-paths src --ignore-src --rosdistro crystal -y --skip-keys "console_bridge fastcdr fastrtps libopensplice67 libopensplice69 rti-connext-dds-5.3.1 urdfdom_headers"

Error seen

 rosdep install --from-paths src --ignore-src --rosdistro crystal -y --skip-keys "console_bridge fastcdr fastrtps libopensplice67 libopensplice69 rti-connext-dds-5.3.1 urdfdom_headers"
executing command [sudo -H apt-get install -y ros-crystal-rosidl-typesupport-connext-cpp]
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package ros-crystal-rosidl-typesupport-connext-cpp
ERROR: the following rosdeps failed to install
  apt: command [sudo -H apt-get install -y ros-crystal-rosidl-typesupport-connext-cpp] failed

If I run the apt-get help, this is what is reported

 sudo -H apt-get install -y ros-crystal-rosidl-typesupport-connext-cpp
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package ros-crystal-rosidl-typesupport-connext-cpp

The developer guide does not mention copyrights on source code files:

Which files should have one? When should an old one be updated? What order should they be in? When making a change, should I add a new copyright to the existing one with my name? With my company name?

Our install instructions for RTI Connext refer to installing 5.3.1, but this does not seem to be available from RTI's website. Only 6.0.0 is available for download, which affects instructions for macOS and Windows.

Places where our instructions are out-dated:

• macOS binary installation
• macOS source installation
• Windows binary installation
• Windows source installation

The ROS 2 tutorial for Releasing a ROS 2 package with bloom just says to follow the ROS 1 Releasing a Package for the First Time. But at the same time, the step 2 of that tutorial says:

Note: This procedure will not work for ROS2 packages, since ROS2 uses a new build system. If using ROS2, you will have to create the changelog and release tags yourself. Please see the ROS 2 Bloom page for more information.

The problem is that the ROS 2 tutorial doesn't mention anything about changelog and release tags creation.

Is the ROS 2 tutorial missing those steps? Or is the note in the ROS 1 tutorial outdated?

The installation instructions installing ROS2 on Windows do not include the installation of development tools like colcon, etc. It would be very useful if the instructions included everything that is needed for ROS2 development (as in Building ROS 2 on Windows).

Maybe this applies to the instructions for other platforms as well (can only speak for Windows right now).

In the last step of "Linux-Install-Debians" documentation page. Under the "Additional packagas using ROS 1 packages". The user is guided on how to work with ros1_bridge, but the command doesn't work.

'sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/'

E: Unable to locate package ros-crystal-turtlebot2-*

With master branches, uncrustify fails to build without patch.exe, which needs to be installed from

http://gnuwin32.sourceforge.net/packages/patch.htm

The ROS 1 environment configuration tutorial implies that switching between distros is as easy as switching out the <distro> in the source command on linux:

$ source /opt/ros/<distro>/setup.bash

Since we're trying to target macOS and Windows as well now, I was hoping we could change the instructions for macOS and Windows binary packages installation guides to include the distro name. That way, the enviroment config tutorial can say "You can switch distros by replacing <distro> in the path name..." without having to differentiate between Linux, macOS and Windows.

I'm not sure if this means just changing the instructions in the docs or actually changing something about the binary packaging for those OSs.

For more context:

Originally posted by @clalancette in #334 (comment)

Originally posted by @clalancette in #334 (comment)

consolidating links, cases in code, etc that have historically been an issue.

Ideas:

• Visibility control
• Scheduling (spurious wakeups)
• exporting stdlib structure symbols
• templating and namespace resolution

I'd suggest putting all of the documentation content in a sub folder. Here are a few reasons:

• I was going to look for the instructions for generating this documentation locally on my machine, so I looked at the README, which is actually the wiki root.
  • I think it would be better if the README were about this repository and how it can be used, e.g. https://github.com/ros2/design/blob/gh-pages/README.md
• If the README is useful, then having less files in the root of the repository will make it more visible.
• There is a Contributing.rst file, but again it's for the wiki content, but because of the name it pops up when you're making a new issue (see: https://help.github.com/articles/setting-guidelines-for-repository-contributors/), which is confusing because it's about contributing to ROS in general.
  • Another option here is to use the .github folder, but I don't know which takes precedence.

I was going to make this a pull request, but I don't know what else needs to check in order for this to work.

Also, to the original reason I ran into this, it would be nice if this were a sphinx project which I could generate locally to test my changes before making a content pull request.

In cross compiling article, looks like there are some repeated items about using ONLY

https://github.com/ros2/ros2_documentation/blame/master/source/Tutorials/Cross-compilation.rst#L58

I guess you also want to introduce BOTH?

see link below... examples didnt work...

http://brisbaneroboticsclub.id.au/install-ros2-foxy-fitzroy-on-nvidia-nano/

Following the OSX binary installation page, the following command under "install rqt dependencies" is failing:

python3 -m pip install pygraphviz pydot

Looks like pygraphviz is unable to find the graphviz, previously installed with brew install graphviz.

Collecting pygraphviz
  Using cached https://files.pythonhosted.org/packages/7e/b1/d6d849ddaf6f11036f9980d433f383d4c13d1ebcfc3cd09bc845bda7e433/pygraphviz-1.5.zip
Building wheels for collected packages: pygraphviz
  Building wheel for pygraphviz (setup.py) ... error
  Complete output from command /usr/local/opt/python/bin/python3.7 -u -c "import setuptools, tokenize;__file__='/private/var/folders/tl/vh0p3k113bx20dnv50s4pv3h0000gn/T/pip-install-i_qa55z_/pygraphviz/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" bdist_wheel -d /private/var/folders/tl/vh0p3k113bx20dnv50s4pv3h0000gn/T/pip-wheel-5wd2cnve --python-tag cp37:
  running bdist_wheel
  running build
  running build_py
  creating build
  creating build/lib.macosx-10.13-x86_64-3.7
  creating build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  copying pygraphviz/release.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  copying pygraphviz/version.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  copying pygraphviz/graphviz.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  copying pygraphviz/__init__.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  copying pygraphviz/agraph.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  creating build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_setup.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_unicode.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_readwrite.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_string.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/__init__.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_html.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_node_attributes.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_drawing.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_subgraph.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_edge_attributes.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_clear.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_layout.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_attribute_defaults.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_graph.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  copying pygraphviz/tests/test_attributes.py -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz/tests
  running egg_info
  writing pygraphviz.egg-info/PKG-INFO
  writing dependency_links to pygraphviz.egg-info/dependency_links.txt
  writing top-level names to pygraphviz.egg-info/top_level.txt
  reading manifest file 'pygraphviz.egg-info/SOURCES.txt'
  reading manifest template 'MANIFEST.in'
  warning: no files found matching '*.png' under directory 'doc'
  warning: no files found matching '*.html' under directory 'doc'
  warning: no files found matching '*.txt' under directory 'doc'
  warning: no files found matching '*.css' under directory 'doc'
  warning: no previously-included files matching '*~' found anywhere in distribution
  warning: no previously-included files matching '*.pyc' found anywhere in distribution
  warning: no previously-included files matching '.svn' found anywhere in distribution
  no previously-included directories found matching 'doc/build'
  writing manifest file 'pygraphviz.egg-info/SOURCES.txt'
  copying pygraphviz/graphviz.i -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  copying pygraphviz/graphviz_wrap.c -> build/lib.macosx-10.13-x86_64-3.7/pygraphviz
  running build_ext
  building 'pygraphviz._graphviz' extension
  creating build/temp.macosx-10.13-x86_64-3.7
  creating build/temp.macosx-10.13-x86_64-3.7/pygraphviz
  clang -Wno-unused-result -Wsign-compare -Wunreachable-code -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers -I/usr/local/include -I/usr/local/opt/openssl/include -I/usr/local/opt/sqlite/include -I/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/include/python3.7m -c pygraphviz/graphviz_wrap.c -o build/temp.macosx-10.13-x86_64-3.7/pygraphviz/graphviz_wrap.o
  pygraphviz/graphviz_wrap.c:3354:12: warning: incompatible pointer to integer conversion returning 'Agsym_t *' (aka 'struct Agsym_s *') from a function with result type 'int' [-Wint-conversion]
      return agattr(g, kind, name, val);
             ^~~~~~~~~~~~~~~~~~~~~~~~~~
  1 warning generated.
  clang -bundle -undefined dynamic_lookup build/temp.macosx-10.13-x86_64-3.7/pygraphviz/graphviz_wrap.o -L/usr/local/lib -L/usr/local/opt/openssl/lib -L/usr/local/opt/sqlite/lib -lcdt -lcgraph -o build/lib.macosx-10.13-x86_64-3.7/pygraphviz/_graphviz.cpython-37m-darwin.so
  installing to build/bdist.macosx-10.13-x86_64/wheel
  running install
  Trying dpkg
  Failed to find dpkg
  Trying pkg-config
  Failed to find pkg-config
  Trying dotneato-config
  Failed to find dotneato-config
  Failed to find dotneato-config
Your Graphviz installation could not be found.
      1) You don't have Graphviz installed:
         Install Graphviz (http://graphviz.org)

      2) Your Graphviz package might incomplete.
         Install the binary development subpackage (e.g. libgraphviz-dev or similar.)

      3) You are using Windows
         There are no PyGraphviz binary packages for Windows but you might be
         able to build it from this source.  See
         http://networkx.lanl.gov/pygraphviz/reference/faq.html

      If you think your installation is correct you will need to manually
      provide path to graphviz include and library. For example:

      pip install pygraphviz --install-option="--include-path=/usr/include/graphviz" --install-option="--library-path=/usr/lib/graphviz/"

      The current setting of library_dirs and include_dirs is:

library_dirs=None

include_dirs=None
error: Error locating graphviz.

Failed building wheel for pygraphviz

Running setup.py clean for pygraphviz

Failed to build pygraphviz

Installing collected packages: pygraphviz

Running setup.py install for pygraphviz ... error

Complete output from command /usr/local/opt/python/bin/python3.7 -u -c "import setuptools, tokenize;file='/private/var/folders/tl/vh0p3k113bx20dnv50s4pv3h0000gn/T/pip-install-i_qa55z_/pygraphviz/setup.py';f=getattr(tokenize, 'open', open)(file);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, file, 'exec'))" install --record /private/var/folders/tl/vh0p3k113bx20dnv50s4pv3h0000gn/T/pip-record-6rau2afj/install-record.txt --single-version-externally-managed --compile:

running install

Trying dpkg

Failed to find dpkg

Trying pkg-config

Failed to find pkg-config

Trying dotneato-config

Failed to find dotneato-config

Failed to find dotneato-config
Your Graphviz installation could not be found.

        1) You don't have Graphviz installed:
           Install Graphviz (http://graphviz.org)

        2) Your Graphviz package might incomplete.
           Install the binary development subpackage (e.g. libgraphviz-dev or similar.)

        3) You are using Windows
           There are no PyGraphviz binary packages for Windows but you might be
           able to build it from this source.  See
           http://networkx.lanl.gov/pygraphviz/reference/faq.html

        If you think your installation is correct you will need to manually
        provide path to graphviz include and library. For example:

        pip install pygraphviz --install-option="--include-path=/usr/include/graphviz" --install-option="--library-path=/usr/lib/graphviz/"

        The current setting of library_dirs and include_dirs is:
library_dirs=None
include_dirs=None

error: Error locating graphviz.

----------------------------------------

Command "/usr/local/opt/python/bin/python3.7 -u -c "import setuptools, tokenize;file='/private/var/folders/tl/vh0p3k113bx20dnv50s4pv3h0000gn/T/pip-install-i_qa55z_/pygraphviz/setup.py';f=getattr(tokenize, 'open', open)(file);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, file, 'exec'))" install --record /private/var/folders/tl/vh0p3k113bx20dnv50s4pv3h0000gn/T/pip-record-6rau2afj/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /private/var/folders/tl/vh0p3k113bx20dnv50s4pv3h0000gn/T/pip-install-i_qa55z_/pygraphviz/

I'm using High Sierra.

We should consider adding a section about the new syntax for ROS-specific command-line arguments. Specifically, since Eloquent the user should wrap them in --ros-args and -- and explicitly mark remaps with --remap (or -r). The remap flag is also required for changing the node name and/or namespace with __node:=new_name and __ns:=/new_namespace. As an example, the following ROS 1 command:

./ros_executable non_ros_arg __node:=node_name __ns:=/namespace foo:=bar non_ros_arg2

Gets translated in ROS 2 as:

./ros_executable non_ros_arg --ros-args -r __node:=node_name -r __ns:=/namespace -r foo:=bar -- non_ros_arg2

I'm using the latest binary installation on High Sierra.
Following the Creating an Action tutorial, I am unable to build the package in the last step:

> colcon build
Starting >>> action_tutorials
--- stderr: action_tutorials
CMake Error at /usr/local/Cellar/cmake/3.13.1/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:137 (message):
  Could NOT find OpenSSL, try to set the path to OpenSSL root folder in the
  system variable OPENSSL_ROOT_DIR (missing: OPENSSL_INCLUDE_DIR)
Call Stack (most recent call first):
  /usr/local/Cellar/cmake/3.13.1/share/cmake/Modules/FindPackageHandleStandardArgs.cmake:378 (_FPHSA_FAILURE_MESSAGE)
  /usr/local/Cellar/cmake/3.13.1/share/cmake/Modules/FindOpenSSL.cmake:412 (find_package_handle_standard_args)
  /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/share/fastrtps/cmake/fastrtps-config.cmake:51 (find_package)
  /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/share/rosidl_typesupport_fastrtps_c/cmake/rosidl_typesupport_fastrtps_c-extras.cmake:6 (find_package)
  /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/share/rosidl_typesupport_fastrtps_c/cmake/rosidl_typesupport_fastrtps_cConfig.cmake:38 (include)
  /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/share/rosidl_default_generators/cmake/rosidl_default_generators-extras.cmake:21 (find_package)
  /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/share/rosidl_default_generators/cmake/rosidl_default_generatorsConfig.cmake:38 (include)
  CMakeLists.txt:21 (find_package)


---
Failed   <<< action_tutorials	[ Exited with code 1 ]

Summary: 0 packages finished [13.0s]
  1 package failed: action_tutorials
  1 package had stderr output: action_tutorials
The file /Users/jacob/action_ws/None does not exist.

I followed the OSX binary installation instructions, using the latest build artifacts from https://ci.ros2.org/view/packaging/job/packaging_osx/1473/.

At the end of the instructions, I try to run the demo talker and get the following output:

> ros2 run demo_nodes_cpp talker
Failed to load entry point 'info': dlopen(/Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/python3.7/site-packages/rosbag2_transport/_rosbag2_transport_py.cpython-37m-darwin.so, 2): Library not loaded: /usr/local/opt/console_bridge/lib/libconsole_bridge.0.4.dylib
  Referenced from: /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/librosbag2.dylib
  Reason: image not found
The C extension '/Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/python3.7/site-packages/rosbag2_transport/_rosbag2_transport_py.cpython-37m-darwin.so' failed to be imported while being present on the system. Please refer to 'https://index.ros.org/doc/ros2/Troubleshooting/#import-failing-even-with-library-present-on-the-system' for possible solutions
Failed to load entry point 'play': dlopen(/Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/python3.7/site-packages/rosbag2_transport/_rosbag2_transport_py.cpython-37m-darwin.so, 2): Library not loaded: /usr/local/opt/console_bridge/lib/libconsole_bridge.0.4.dylib
  Referenced from: /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/librosbag2.dylib
  Reason: image not found
The C extension '/Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/python3.7/site-packages/rosbag2_transport/_rosbag2_transport_py.cpython-37m-darwin.so' failed to be imported while being present on the system. Please refer to 'https://index.ros.org/doc/ros2/Troubleshooting/#import-failing-even-with-library-present-on-the-system' for possible solutions
Failed to load entry point 'record': dlopen(/Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/python3.7/site-packages/rosbag2_transport/_rosbag2_transport_py.cpython-37m-darwin.so, 2): Library not loaded: /usr/local/opt/console_bridge/lib/libconsole_bridge.0.4.dylib
  Referenced from: /Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/librosbag2.dylib
  Reason: image not found
The C extension '/Users/jacob/ros2_dashing_prerelease_install/ros2-osx/lib/python3.7/site-packages/rosbag2_transport/_rosbag2_transport_py.cpython-37m-darwin.so' failed to be imported while being present on the system. Please refer to 'https://index.ros.org/doc/ros2/Troubleshooting/#import-failing-even-with-library-present-on-the-system' for possible solutions
[INFO] [talker]: Publishing: 'Hello World: 1'
[INFO] [talker]: Publishing: 'Hello World: 2'
[INFO] [talker]: Publishing: 'Hello World: 3'
...

just did
sudo apt-get install python3-sphinx
git clone https://github.com/ros2/ros2_documentation.git
cd ros2_documentation/
make html
on a ubuntu 18.04 failed as still python3 is not the default. May you please change the documention to
sudo apt-get install python-sphinx
or even suggest somewhere to set python3 as default in the documentation ?