install package by rosdep key name fails

[christianrauch]

The documentation on how to check and install rosdep packages (https://github.com/ros-infrastructure/rosdep/blob/master/doc/overview.rst#installating-rosdeps) seems to be out of date or at least not complete.

At least, I cannot reproduce the commands there.

Example, installing std_msgs for rolling:

docker run -it --rm ubuntu:24.04 bash -c "
export DEBIAN_FRONTEND=noninteractive PIP_BREAK_SYSTEM_PACKAGES=1 && \
apt update && apt -y install python3-pip && \
pip3 install rosdep && \
rosdep init && rosdep update && \
rosdep install -s std_msgs --rosdistro=rolling
"

This should produce a similar #[apt] Installation commands: output as per documentation, but fails with:

ERROR: Rosdep cannot find all required resources to answer your query
Missing resource std_msgs

The key works with rosdep resolve std_msgs --rosdistro=rolling though.

Can you update the documentation to reflect any recent changes on the user-facing behaviour of rosdep? In particular, how to install packages by their rosdep key name.

[cottsay]

This mechanism worked in ROS 1 using the ROS_PACKAGE_PATH environment variable. That variable is not set in ROS 2, so rosdep can't figure out where the std_msgs package is. All of the ROS 2 instructions using rosdep make use of the --from-path option.

The docs should indeed be updated.

[christianrauch]

It would indeed be quite useful, if you could use rosdep to resolve a key to a package name or the install command that is used to install packages.