Usage of 'rosdep keys' argument is unclear from documentation

[firesurfer]

I am currently trying to debug why xacro is not picked up as a dependency from a package (aka not installed in the ci pipeline).

According to the documentation the rosdep keys command can be used to list all dependencies of a package.

rosdep keys ...
list the rosdep keys that the packages depend on.

When i now run:

rosdep keys --from-paths ./src <my package name> from the root directory of my local workspace I always get the error:

given path '<my package name>' does not exist

The official documentation: http://docs.ros.org/en/independent/api/rosdep/html/commands.html only provides the same information as the rosdep --help command.

Also the guide in the "normal" documentation: https://docs.ros.org/en/jazzy/Tutorials/Intermediate/Rosdep.html does not provide any further information.

Question

So the question is:

1. How do list all dependencies of a package
2. Can I also check if these dependencies are installable

[firesurfer]

A friendly ping

[christophebedard]

Looks like rosdep keys expects a path to a package, not just a package name. Also, from my understanding, I think --from-paths effectively limits how deep the search for keys goes:

1. rosdep keys <path_to_pkg> --from-paths <path_to_pkg>: returns the package's direct dependencies (i.e., strictly listed in its package.xml)
2. rosdep keys <path_to_pkg> --from-paths <path>: returns all keys for direct and indirect dependencies, but only searching in the given path
   • For example, if your package (<path_to_pkg>) only depends on pkgA and that package is in <path>, but pkgA's dependencies are not in <path>, then you'd only get pkgA + pkgA's direct dependencies.

I agree that the documentation/--help is not very helpful. This could probably be made clearer:

rosdep/src/rosdep2/main.py

Lines 102 to 103 in 2a0510e

	rosdep keys <stacks-and-packages>...
	list the rosdep keys that the packages depend on.

.

[christophebedard]

2. rosdep keys <path_to_pkg> --from-paths <path>: returns all keys for direct and indirect dependencies, but only searching in the given path
   • For example, if your package (<path_to_pkg>) only depends on pkgA and that package is in <path>, but pkgA's dependencies are not in <path>, then you'd only get pkgA + pkgA's direct dependencies.

Ah, this might not even be true. The package I tried this on has no dependencies on any packages in <path>, and yet I get a bunch of keys, including packages that actually depend on my package.

[christophebedard]

In any case, if you can figure out how it's meant to work, improving the documentation would definitely be appreciated 😄