Rust bootstraps via i686?

Rust bootstraps via i686?

[Adam Van Ymeren]

Does anyone know why rust bootstraps itself from the i686 version of the
binaries even if you're running on x86_64?

This results in having to download a build a lot of packages to build
rust on x86_64.

If I can make it bootstrap though the current system in use would that
be a useful patch or is there some problem with bootstraping from x86_64
that I'm unaware of?

Thanks!
-Adam

Re: Rust bootstraps via i686?

[Efraim Flashner]

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On Mon, Dec 04, 2017 at 02:56:39PM -0500, Adam Van Ymeren wrote:
> Does anyone know why rust bootstraps itself from the i686 version of the
> binaries even if you're running on x86_64?
> 
> This results in having to download a build a lot of packages to build
> rust on x86_64.
> 
> If I can make it bootstrap though the current system in use would that
> be a useful patch or is there some problem with bootstraping from x86_64
> that I'm unaware of?
> 
> Thanks!
> -Adam
> 

I believe the reason is to decrease the number of language-specific
bootstrap binaries. Since the i686 bootstrap rust is capable of building
for i686 and for x86_64, it means one less binary.

On the other hand, this does nothing for the other architectures which
can't execute i686 code natively.

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Re: Rust bootstraps via i686?

[ng0]

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Efraim Flashner transcribed 2.1K bytes:
> On Mon, Dec 04, 2017 at 02:56:39PM -0500, Adam Van Ymeren wrote:
> > Does anyone know why rust bootstraps itself from the i686 version of the
> > binaries even if you're running on x86_64?
> > 
> > This results in having to download a build a lot of packages to build
> > rust on x86_64.
> > 
> > If I can make it bootstrap though the current system in use would that
> > be a useful patch or is there some problem with bootstraping from x86_64
> > that I'm unaware of?
> > 
> > Thanks!
> > -Adam
> > 
> 
> I believe the reason is to decrease the number of language-specific
> bootstrap binaries. Since the i686 bootstrap rust is capable of building
> for i686 and for x86_64, it means one less binary.
> 
> On the other hand, this does nothing for the other architectures which
> can't execute i686 code natively.

I think when we've added rustc, rust did not support as many architectures
as it does now.
There's now an aarch64 and powerpc download in addition to i686+x86_64,
and mipsel, in many flavors.

As long as mrustc to bootstrap rustc is not working without rustc, we
will get problems for example for aarch64 with the i686 bootstrap binary,
right?

> 
> -- 
> Efraim Flashner   <efraim@flashner.co.il>   אפרים פלשנר
> GPG key = A28B F40C 3E55 1372 662D  14F7 41AA E7DC CA3D 8351
> Confidentiality cannot be guaranteed on emails sent or received unencrypted



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Re: Rust bootstraps via i686?

[Danny Milosavljevic]

Hi Adam,

On Mon, 04 Dec 2017 14:56:39 -0500
Adam Van Ymeren <adam@vany.ca> wrote:

> Does anyone know why rust bootstraps itself from the i686 version of the
> binaries even if you're running on x86_64?

It's to cut down on the number of weird binary blobs we use.

> If I can make it bootstrap though the current system in use would that
> be a useful patch

That would be nice, yes.

In the long term, it would be even better to bootstrap from mrust, a C++ implementation of Rust, and remove all the binary blobs.

> or is there some problem with bootstraping from x86_64
> that I'm unaware of?