That MIT license only applies to the Julia wrapper code. The package downloads and dynamically links into an FFTW shared library, which means any code that uses it needs to be GPL if distributed as a whole.
> Note that FFTW is licensed under GPLv2 or higher (see its license file), but the bindings to the library in this package, FFTW.jl, are licensed under MIT. This means that code using the FFTW library via the FFTW.jl bindings is subject to FFTW's licensing terms.
If you have an idea on how to make that clearer, we would be happy to review a PR to the FFTW.jl repository.
My mistake, docs there are fine. A few other BinaryBuilder-using packages have neglected to mention this issue, last I checked. And BTW BinaryBuilder is violating even MIT licenses if you don't package and include the license file along with the shared-library download.
staticfloat|7 years ago
> Note that FFTW is licensed under GPLv2 or higher (see its license file), but the bindings to the library in this package, FFTW.jl, are licensed under MIT. This means that code using the FFTW library via the FFTW.jl bindings is subject to FFTW's licensing terms.
If you have an idea on how to make that clearer, we would be happy to review a PR to the FFTW.jl repository.
[0] https://github.com/JuliaMath/FFTW.jl
tavert|7 years ago