You're reading the documentation for an older, but still supported, version of ROS 2. For information on the latest version, please have a look at Humble.

Fedora (source)

How to setup the development environment?

The following system dependencies are required to build ROS 2 on Fedora. They can be installed with dnf as follows:

sudo dnf install \
  asio-devel \
  cmake \
  cppcheck \
  eigen3-devel \
  gcc-c++ \
  liblsan \
  libXaw-devel \
  libyaml-devel \
  make \
  opencv-devel \
  patch \
  python3-argcomplete \
  python3-colcon-common-extensions \
  python3-coverage \
  python3-devel \
  python3-empy \
  python3-lark-parser \
  python3-lxml \
  python3-mock \
  python3-mypy \
  python3-nose \
  python3-pip \
  python3-pydocstyle \
  python3-pyflakes \
  python3-pyparsing \
  python3-pytest \
  python3-pytest-cov \
  python3-pytest-mock \
  python3-pytest-runner \
  python3-rosdep \
  python3-setuptools \
  python3-vcstool \
  python3-yaml \
  poco-devel \
  poco-foundation \
  python3-flake8 \
  python3-flake8-import-order \
  redhat-rpm-config \
  tinyxml-devel \
  tinyxml2-devel \
  uncrustify \
  wget

With this done, you can follow the rest of the instructions to fetch and build ROS 2.