Update ruby rosdep key facets for Focal, and add new keys metaruby and utilrb

[meyerj]

Those packages are dependencies of orogen. Currently it is not planned to release orogen into ROS like it was the case until indigo. But it is still possible to build from source (orocos-toolchain/orogen#140 (comment)), and it would be nice if rosdep can install its dependencies without custom rosdep files like the one we provide in orocos-docker-images/ros2/ubuntu/prereqs.yaml.

Those are gem dependencies. Package ruby-facets is not available anymore for Ubuntu Focal (and newer?) and also needs to be installed as a gem now:

• facets: https://rubygems.org/gems/facets
• metaruby: https://rubygems.org/gems/metaruby
• utilrb: https://rubygems.org/gems/utilrb

Questions:

• Probably better to list keys bionic and xenial explicitly for facets, and use '*' for focal and newer? Likely the package won't come back.
• I did not test all distributions for the new keys, and assumed that gem would work the same way in all major distributions. Only Ubuntu bionic and focal have been actually tested. Do you prefer to only define the keys for Ubuntu, or even the tested versions? If not, is it possible to omit the OS_NAME or just write '*': if all resolve to the same installer and package? It is probably the same for some Python packages which are only available via pip.

[tfoote]

Probably better to list keys bionic and xenial explicitly for facets, and use '*' for focal and newer? Likely the package won't come back.

Yes, it's better to list all the old versions explicitly and have the '*' rule carry into the future.

Unfortunately the installer and os name levels don't support wildcard syntax. It's probably better to simply reduce it to the ones you're confident on. The extra lines there if they're unused will just be more to maintain.

[jacobperron]

I'm not sure why CI is failing, but I suspect it might be because there already exist rosdistro keys for metaruby and utilrb in indigo.yaml (and older). Maybe we could remove the keys from the EOL distros or prefix the new keys with ruby- (or something). @tfoote @nuclearsandwich Thoughts?

[cottsay]

Shouldn't the values being added be lists of package names and not bare strings?

[hidmic]

@cottsay has a point. @meyerj mind to take a look?

[meyerj]

@cottsay has a point. @meyerj mind to take a look?

Done: 0919587

I thought the list notation is optional, and there are examples without list brackets in the rosdep.yaml spec in REP-111, but it is still good to add them consistently.