Hello,

I'm not sure if it's correct, but I changed the license from gpl3+ to
gpl2+ to keep it consistent with the r-markdown package
(https://www.gnu.org/licenses/gpl-faq.html#v2v3Compatibility). Thanks
for figuring that out.

New patch attached.

2015-09-14 8:17 GMT-03:00 Ricardo Wurmus <ricardo.wurmus@mdc-berlin.de>:
> Hi Vicente,
>
>> From 36f94f07cba5edea4897ac36b92a73bfc6a3258b Mon Sep 17 00:00:00 2001
>> From: Vicente Vera Parra <vicentemvp@gmail.com>
>> Date: Sun, 13 Sep 2015 13:20:29 -0300
>> Subject: [PATCH 11/19] gnu: Add r-knitr.
>
>> * gnu/packages/statistics.scm (r-knitr): New variable.
>
> [...]
>
>> +    (synopsis "General-Purpose Package for Dynamic Report Generation in R")
>> +    (description
>> +     "Provides a general-purpose tool for dynamic report generation in
>> +R using Literate Programming techniques.")
>
> As before, please provide a better description (at least by replacing
> “Provides” in the first sentence with “This package provides”); and use
> lower-case in the synopsis.
>
>> +    (license license:gpl3+)))
>
> I don’t think this is correct.  The package actually doesn’t declare the
> version of the GPL.  There are no license headers I could find and all
> it says is
>
>     “This package is free and open source software, licensed under GPL.”
>
> Furthermore, as noted before, there might be a license conflict when
> combining “r-knitr” with “r-markdown”, because the latter is released
> under “GPLv2 only”.
>
> I just asked the author about what version of the GPL was intended
> here[1].
>
> ~~ Ricardo
>
> [1]: https://github.com/yihui/knitr/issues/566#issuecomment-140042571