Add python3-typeshed

[InvincibleRMC]

Please add the following dependency to the rosdep database.

Package name:

python3-typeshed

Package Upstream Source:

https://github.com/python/typeshed

Purpose of using this:

In the process of accomplishing ros2/rclpy#1257 we need the types for pyyaml being used for mypy support.

The source is here:

https://packages.ubuntu.com/jammy/amd64/python/python3-typeshed
https://packages.debian.org/search?suite=default&section=all&arch=any&searchon=names&keywords=python3-typeshed

[sloretz]

Since this is a pip only key we won't be able to make rclpy (or any package released to the ROS build farm) depend on it. Does it still work for your purposes?

[InvincibleRMC]

Ah ok. I should be able to switch it to the python3-typeshed apt package. However that will install slighty more stuff and only exist on Ubuntu 22+.

[cottsay]

It looks like mypy on Debian, Ubuntu, and Fedora doesn't actually use a discrete "typeshed" package even if available, and rather bundles typeshed as mypy.typeshed. Would it be possible to use that instead, since your long-term goal is to use mypy anyway?

[InvincibleRMC]

The CI is failing because python3-typeshed doesn't exist on Ubuntu 20. Should I disable it for that older version? And if so how?

[InvincibleRMC]

It looks like mypy on Debian, Ubuntu, and Fedora doesn't actually use a discrete "typeshed" package even if available, and rather bundles typeshed as mypy.typeshed. Would it be possible to use that instead, since your long-term goal is to use mypy anyway?

From what I can tell mypy.typeshed only has stdlib types and not typeshed's stubs folders. From testing this without installing python3-typeshed or types-pyyaml mypy raises the following.

src/rclpy/rclpy/rclpy/parameter.py:27: error: Library stubs not installed for "yaml"  [import-untyped]
src/rclpy/rclpy/rclpy/parameter.py:27: note: Hint: "python3 -m pip install types-PyYAML"

[cottsay]

From what I can tell mypy.typeshed only has stdlib types and not typeshed's stubs folders.

Thanks for checking.

Is my understanding correct in saying that your goal is to have the PyYAML stubs? I'm asking mainly because there is no python3-typeshed package available for RHEL 9, which is a tier-2 platform for ROS 2. However, it does appear that the individual stubs are packaged.

I think it would be appropriate to go back to the python3-types-pyyaml key you had before, but add rules for Debian/Ubuntu for python3-typeshed under it. Then you could add python3-types-pyyaml rules for Fedora and RHEL as well. A rosdep "key" really represents a resource, so if the python3-typeshed deb provides what you'd expect for python3-types-pyyaml, then it should be okay (even though you get a little more than you needed).

There is precedent for this pattern in other packages in rosdep. Different distributions make different decisions regarding where to draw lines when separating subpackages. Boost is another example of where major distributions make different decisions. It's unfortunate that there is no Ubuntu package specifically for the PyYAML types because that's typically how we derive the name of the rosdep key, but I think python3-types-pyyaml would probably be the package name if it did exist.

[sloretz]

• Debian: https://packages.debian.org/bookworm/python3-typeshed
• Fedora: https://packages.fedoraproject.org/pkgs/python-types-pyyaml/python3-types-pyyaml/
• Ubuntu: https://packages.ubuntu.com/jammy/amd64/python/python3-typeshed
• PyPI: https://pypi.org/project/types-PyYAML/
• Rhel: https://packages.fedoraproject.org/pkgs/python-types-pyyaml/python3-types-pyyaml/