On Tue, Jan 25, 2011 at 22:52, Chris Smith
On Tue, 2011-01-25 at 22:34 -0800, John Millikin wrote:
The specific claim I'm refuting is that if some library or application depends on GPL'd code, that library/application must itself be GPL-licensed. This claim is simply not true. The GPL only applies to derived works, such as binaries or copied code.
Well, binaries (among other things) are pretty much exactly what's at issue here. I don't think anyone disputes that you can copy and paste sections of BSD3 licensed source code into a new project, but that wasn't the point brought up. If you actually install the thing from Hackage, you build a binary, which links in code from the GPLed library, and distributing the result is covered by the terms of the GPL.
It's not possible for a .cabal file to specify which license the final binaries will use -- it depends on what libraries are locally installed, what flags the build uses, and what the executables themselves link. The best Cabal could do is, after finishing "cabal build" on an executable, printing out which licenses apply: $ cabal build some-pkg --flags=enable-some-exc ... Executable 'some-exc' has licenses: BSD3 GPL3 PublicDomain Executable 'some-other-exc' has licenses: BSD3 GPL3 ** Note: 'some-other-exc' links against external system libraries. Additional libraries may apply. Executable 'another-exc' has licenses: MIT PublicDomain ... $ Since it's impossible for Cabal/Hackage to work as you describe, it's only sensible to interpret the "license" field as applying to the source code archive.