RFC: New license attribute for license text/expression addition

[AyanSinhaMahapatra]

There are licenses which are is_exception: True and these actually should be paired with the licenses they are an exception to,
in the case of generating attribution and also while getting the resultant license expression if detected.
See https://github.com/nexB/scancode-toolkit/blob/develop/src/licensedcode/data/licenses/openssl-exception-gpl-2.0.LICENSE for an example. We can implement this by adding a new license attribute which points to the license key which this exception is related to. This will be a list btw as there can be licenses without versions, but we have to see which one of these to include for text/expressions.

Suggestions:

• exception_to
• include_text_from

Also similar issue, but a bit different: #3248 (comment)

[pombredanne]

In #3248 (comment) I also suggest an alternative way: use a new implied_expression attribute and that may be able to handle both the exception_to and include_text_from attributes purpose?

[sschuberth]

There are licenses which are is_exception: True and these actually should be paired with the licenses they are an exception to

This would be awesome; in ORT we currently post-process ScanCode results to do exactly this grouping / association of stand-alone exception findings with nearby license findings.