[R-pkg-devel] Possible open-source license incompatibilities within R packages

[Ivan Krylov]

On Mon, 8 Sep 2025 17:55:52 +0300
Ilmari Tamminen <ilmari.tamminen using icloud.com> wrote:

> Are the GPL-2 upstream licenses a problem for my GPL-3 R code? If so,
> are there recommended ways of resolving this?

The _safest_ (possibly overly strict) assumption is that your package
is a derived work of your GPL-2 dependencies even when they are not
direct but transitive (which is the position taken by GPL FAQ), which
necessitates licensing your code under GPL >= 2.

This is not the only possibility. You could make various arguments that
would let you keep your code licensed under GPL-3.0-only (e.g. does your
GPL-3 code work even with the GPL-2 dependency uninstalled? do other
non-GPL2 libraries implement the same interface?), but whether they are
valid in your specific case, only a lawyer who specialises in software
can say.

-- 
Best regards,
Ivan