Well, Rust is MIT + Apache 2.0, so they can do this. It isn't copyleft.
Personally I consider it a a shame that rust and it's ecosystem isn't at least weakly copyleft (e.g. LGPL or MPL) though there are some good reasons not to use those specifically. (LGPL isn't not well defined if you don't use dynamic linking, MPL is younger than rust, but would have been an excellent fit otherwise). And the ecosystem follows the leader for the most part.
But that is neither here nor there, and I'm not interested in arguing about licenses on the Internet. :)
Well, Rust is MIT + Apache 2.0, so they can do this. It isn't copyleft.
Personally I consider it a a shame that rust and it's ecosystem isn't at least weakly copyleft (e.g. LGPL or MPL) though there are some good reasons not to use those specifically. (LGPL isn't not well defined if you don't use dynamic linking, MPL is younger than rust, but would have been an excellent fit otherwise). And the ecosystem follows the leader for the most part.
But that is neither here nor there, and I'm not interested in arguing about licenses on the Internet. :)