Re: [PATCH] Add rpy2.

[韋嘉誠]

On Jul 20, 2015 5:56 PM, "Ludovic Courtès" <address@hidden> wrote:
> "Claes Wallin (韋嘉誠)" <address@hidden> skribis:

> >> > +    (license gpl2+)))
> >>
> >> R being GPLv3+, this should be the same.
> >
> > I understand the reasoning that a package is more user-oriented than
> > developer-oriented and should reflect the license of the whole, but there's
> > an argument for reflecting the original license as well. Has this been
> > discussed?
>
> This has been mentioned in past reviews.  Basically the intent is for
> ‘license’ to reflect the license of the whole, but we often end up
> leaving a comment in cases where there’s some ambiguity.
>
> I think it’s hard to do better without maintaining ‘copyright’ files
> à la Debian.

I suddenly had an idea. There is a directional compatibility graph between the most common licenses. That means calculating the license of a package can often be trivial, at least a conservative guess.

You could just "guix license python-rpy2" and it would tell you that the code itself is GPLv2+ (because package definition says so), but because of dependencies the package as installed is effectively GPLv3+. Except when you can't, so there should be an "it's complicated" state as well, possibly resolvable through manual hints in package defs.

This could be a check in lint as well, to make sure e.g. no GPLv2 package relies on a GPLv3 package without an explanation. Defining exactly in what way a package depends on another (i.e. if it makes it a derivative) could be a later excercise.