You're reading the documentation for a version of ROS 2 that has reached its EOL (end-of-life), and is no longer officially supported. If you want up-to-date information, please have a look at Iron.

Building ROS 2 on macOS

System requirements 

We support macOS 10.12.x.

However, some new versions like 10.13.x and some older versions like 10.11.x and 10.10.x are known to work as well.

Install prerequisites 

You need the following things installed to build ROS 2:

Xcode
- If you don’t already have it installed, install Xcode and the Command Line Tools:
```
xcode-select --install
```
brew (needed to install more stuff; you probably already have this):
- Follow installation instructions at http://brew.sh/
- Optional: Check that brew is happy with your system configuration by running:
```
brew doctor
```
  Fix any problems that it identifies.
You also need a Java runtime installed, which you can get here.

Use brew to install more stuff:

brew install cmake cppcheck eigen pcre poco python3 tinyxml wget

# install dependencies for Fast-RTPS if you are using it
brew install asio tinyxml2

brew install opencv

# install dependencies for rcl_logging_log4cxx
brew install log4cxx

Install rviz dependencies

# install dependencies for Rviz
brew install qt freetype assimp

# Add the Qt directory to the PATH and CMAKE_PREFIX_PATH
export CMAKE_PREFIX_PATH=$CMAKE_PREFIX_PATH:/usr/local/opt/qt
export PATH=$PATH:/usr/local/opt/qt/bin

Use python3 -m pip (just pip may install Python3 or Python2) to install more stuff:

python3 -m pip install argcomplete catkin_pkg colcon-common-extensions coverage empy flake8 flake8-blind-except flake8-builtins flake8-class-newline flake8-comprehensions flake8-deprecated flake8-docstrings flake8-import-order flake8-quotes lark-parser mock nose pep8 pydocstyle pyparsing setuptools vcstool

Optional: if you want to build the ROS 1<->2 bridge, then you must also install ROS 1:
- Start with the normal install instructions: https://wiki.ros.org/kinetic/Installation/OSX/Homebrew/Source
- When you get to the step where you call rosinstall_generator to get the source code, here’s an alternate invocation that brings in just the minimum required to produce a useful bridge:
```
rosinstall_generator catkin common_msgs roscpp rosmsg --rosdistro kinetic --deps --wet-only --tar > kinetic-ros2-bridge-deps.rosinstall
wstool init -j8 src kinetic-ros2-bridge-deps.rosinstall
```
  Otherwise, just follow the normal instructions, then source the resulting install_isolated/setup.bash before proceeding here to build ROS 2.

Disable System Integrity Protection (SIP)

macOS/OS X versions >=10.11 have System Integrity Protection enabled by default. So that SIP doesn’t prevent processes from inheriting dynamic linker environment variables, such as DYLD_LIBRARY_PATH, you’ll need to disable it following these instructions.

Get the ROS 2 code 

Create a workspace and clone all repos:

mkdir -p ~/ros2_crystal/src
cd ~/ros2_crystal
wget https://raw.githubusercontent.com/ros2/ros2/crystal/ros2.repos
vcs import src < ros2.repos

Install additional DDS vendors (optional)

If you would like to use another DDS or RTPS vendor besides the default, eProsima’s Fast RTPS, you can find instructions here.

Build the ROS 2 code 

Note: if you are trying to build the ROS 1 <-> ROS 2 bridge, follow instead these modified instructions.

Run the colcon tool to build everything (more on using colcon in this tutorial):

cd ~/ros2_crystal/
colcon build --symlink-install

Environment setup 

Source the ROS 2 setup file:

. ~/ros2_crystal/install/setup.bash

This will automatically set up the environment for any DDS vendors that support was built for.

Try some examples 

In one terminal, set up the ROS 2 environment as described above and then run a C++ talker:

. ~/ros2_crystal/install/setup.bash
ros2 run demo_nodes_cpp talker

In another terminal source the setup file and then run a Python listener:

. ~/ros2_crystal/install/setup.bash
ros2 run demo_nodes_py listener

You should see the talker saying that it’s Publishing messages and the listener saying I heard those messages. This verifies both the C++ and Python APIs are working properly. Hooray!

See the tutorials and demos for other things to try.

If you installed your workspace with colcon as instructed above, “uninstalling” could be just a matter of opening a new terminal and not sourcing the workspace’s setup file. This way, your environment will behave as though there is no Crystal install on your system.
If you’re also trying to free up space, you can delete the entire workspace directory with:
```
rm -rf ~/ros2_crystal
```