Feature Request: REUSE compliance

The REUSE standard from the Free Software Foundation Europe helps clarify license information in open-source projects. To be REUSE-compliant, every file in a Git repository has to have license information, which is either stored in the header of the file as a comment, or as a separate text file with the .license extension. More details in the REUSE tutorial.

I would like to make my research projects REUSE-compliant and use Packrat.

Every source code package in packrat/src comes with its own license, which can be found in the DESCRIPTION file. In order to create the .license file for a package, I would need to extract the license, copyright holders, and year from DESCRIPTION manually. That is a lot of effort and prone to errors.

My feature suggestion:

• Packrat automatically generates .license files alongside every tar.gz package source file.
• Packrat adds the REUSE license header to the files it generates in the packrat folder, namely init.R, packrat.opts, and packrat.lock. I suggest the config files to be in the public domain under CC0-1.0, as suggested by the REUSE tutorial.

Start by tracing how Packrat creates tar.gz package sources from packages under packrat/src and reads each package's DESCRIPTION. Then inspect generation of init.R, packrat.opts, and packrat.lock; done means generated package .license files contain extracted metadata and generated Packrat files carry the requested REUSE/CC0-1.0 licensing information.