Erast Benson wrote:
> I do not need to make the build system
> available under GPL (GPL §3 requires me to make it available but does
> not mention a license)
GPL 3(a) requires the "complete corresponding source code [be]
distributed under the terms of Sections 1 and 2 above....". GPL 3
defines the source code to include the "the scripts used to control
compilation and installation of the executable."
Section 2(b) requires third parties to publish derived works under the
GPL ("to be licensed as a whole at no charge to all third parties under
the terms of this License."). Section 2 also states "[T]he distribution
of the whole must be on the terms of this License, whose permissions for
other licensees extend to the entire whole, and thus to each and every
part regardless of who wrote it."