ros2 pkg create: resource files not installed

How have people been testing ros2 pkg create? I tried to run it but the templates aren’t installed so I get:

$ ros2 pkg create dummy_package --license asdf
going to create a new package
package name: dummy_package
destination directory: /tmp
package format: 2
version: 0.0.0
description: TODO: Package description
maintainer: ['dhood <[e-mail]>']
licenses: ['asdf']
build type: ament_cmake
dependencies: []
creating folder ./dummy_package
Traceback (most recent call last):
  File "/home/dhood/ros2_ws/install_isolated/ros2cli/bin/ros2", line 11, in <module>
    load_entry_point('ros2cli==0.4.0', 'console_scripts', 'ros2')()
  File "/home/dhood/ros2_ws/install_isolated/ros2cli/lib/python3.5/site-packages/ros2cli/cli.py", line 69, in main
    rc = extension.main(parser=parser, args=args)
  File "/home/dhood/ros2_ws/install_isolated/ros2pkg/lib/python3.5/site-packages/ros2pkg/command/pkg.py", line 39, in main
    return extension.main(args=args)
  File "/home/dhood/ros2_ws/install_isolated/ros2pkg/lib/python3.5/site-packages/ros2pkg/verb/create.py", line 154, in main
    create_package_environment(package, args.destination_directory)
  File "/home/dhood/ros2_ws/install_isolated/ros2pkg/lib/python3.5/site-packages/ros2pkg/api/create.py", line 97, in create_package_environment
    package_xml_config)
  File "/home/dhood/ros2_ws/install_isolated/ros2pkg/lib/python3.5/site-packages/ros2pkg/api/create.py", line 71, in _create_template_file
    raise FileNotFoundError('template not found:', template_path)
FileNotFoundError: [Errno template not found:] /home/dhood/ros2_ws/install_isolated/ros2pkg/lib/python3.5/site-packages/ros2pkg/resource/package_environment/package.xml.em

Do I need to run it from a particular directory or anything? Or do we just need to install the resource files (I don’t see how they are being installed currently).

I am posing this as a question because it might be user error, given that I am the first one to run into it when it seems that others were testing it out in https://github.com/ros2/ros2cli/pull/42

[dhood]

I am happy to fix it, it shouldn’t be a big change, I just wanted to confirm that the fix was needed. I appreciate from the outside it seems like a strange question, but there are a number of setup.py tricks that I am still learning e.g. there are non-obvious installation commands like data_files that I may have overlooked, and in the past we’ve also added test commands that didn’t work unless you had particular python packages installed, so it was a genuine question that I had about if it was something I was missing.

I think that data_files is the appropriate approach for this so I will create a PR in that direction unless something else makes sense here.

[dhood]

updating what resulted in https://github.com/ros2/ros2cli/pull/87 (including a new setup.py trick):

data_files will install to ~/ros2_ws/install_isolated/ros2pkg instead of, e.g., ~/ros2_ws/install_isolated/ros2pkg/lib/python3.5/site-packages/ros2pkg/, where the files were originally being looked for.

They can be installed to the site-packages path using the package_data setup.py option.

When they are installed that way, they can be accessed via pkg_resources.resource_filename('ros2pkg', 'resource/' + template_file_name) or similar. Something I learnt is that the input to that function is not a filestystem path, per say, and this page says: “Do not use os.path routines to manipulate resource paths, as they are not filesystem paths.” What will be returned by that function is a filesystem path, though it might be a path to a cache directory if the resources were installed in a compressed manner and so needed to be extracted first.