I see it as part of portability that you do not need to use any external system for bootstrapping.
Imagine as a developer who compiles base from source you had to find another system only to compile rustc and then transfer it to your machine. And you would not have to do this only once, but for every compiler bug fix coupled with the overall rapid evolution of Rust. I think many in the OpenBSD community would oppose such an approach, even without further considering other aspects such as security implications.
This is the case IIRC with Android - even though I want to build it for a 32-bit ARM architecture, I can't build it on anything but 64-bit. I guess the vast majority of Android systems cannot even compile Android!
> I see it as part of portability that you do not need to use any external system for bootstrapping.
You always need an external system for bootstrapping, you're not assembling the base C compiler with which you're compiling everything else. At one point you need to obtain a compiler from somewhere else.
...And the point is that the OpenBSD project has a policy of self-hosting. The bootstrap compiler for base (along with everything else needed to build base) must exist in base.
Imagine as a developer who compiles base from source you had to find another system only to compile rustc and then transfer it to your machine. And you would not have to do this only once, but for every compiler bug fix coupled with the overall rapid evolution of Rust. I think many in the OpenBSD community would oppose such an approach, even without further considering other aspects such as security implications.