Also pertinent:

This program is listed in https://directory.fsf.org/wiki/Unrar-free

J'

On Thu, Mar 02, 2017 at 06:54:24AM +0100, John Darrington wrote:
     I don't have any strong opinions here.  But if somebody feels that we really cannot
     have this program in Guix, then go ahead and revert it.
     
     In the meantime I will try to contact the authors and ask for clarification.  However
     since the project has been inactive for the last 13 years, I don't hold too much 
     hope of getting a reply.
     
     J'
     
     On Wed, Mar 01, 2017 at 10:19:59PM +0100, Cl??ment Lassieur wrote:
          >> Like you say, the authors have taken GPL code from another project and incorporated
          >> it into unrar - that is only possible if the the resultant work is GPL compatible.
          >
          > Or if the resultant work is illegal?
          
          Actually, unrarlib is dual-licensed, so it is possible to use it within
          a proprietary program (see http://www.unrarlib.org/license.html).
          
          But I'll trust you that COPYING is enough :)  Sorry for bothering you
          then.
          
     
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