Make `--fetch-license` its own subcommand instead of a gen option

[chinyeungli]

We can even fetch ABOUT files, notices etc... from dejacode

[mjherzog]

We need to be clear about any ABC Tookit functions/features that require a DejaCode subscription - these always need to be optional.

[chinyeungli]

One of the features for having --fetch-license as an option from gen is the tool can update the license_name and license_file fields in the ABOUT files.

if we make the --fetch-license as a subcommand, the tool can fetch and create .LICENSE with no problem, but the ABOUT file may not have a "proper" reference to reference the fetched license. For instance, the ABOUT file may only have the license_expression field but does not have the license_name or license_file field.

[pombredanne]

The --fetch-license option should be a separate sub-command that fetches and stores license texts and data in a reference directory that can then be used at ABOUT generation time.
It can use the same approach as ScanCode to store license data in YAML files. Then these licenses (and any other licenses) can be referenced when generating ABOUT files.
I am scheduling this for 4.0

[mjherzog]

Does this mean an option to pull license text from the ScanCode license repo?

[pombredanne]

@mjherzog for instance yes.

[pombredanne]

This is fixed in https://github.com/nexB/aboutcode-toolkit/tree/361-make-transform-work branch