Re: bootstrapping scenario for a package

[Efraim Flashner <efraim@flashner.co.il>]

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On Sun, Dec 19, 2021 at 11:03:25PM -0800, Andy Tai wrote:
> Hi, I was trying to update mono to the current release version.  The
> build step as documented actually says to download a minimal C#
> compiler from the mono site which is then used to compile the rest of
> the source to build the full system.   I looked and did not find the
> source of this minimal compiler--so it is a black box in a way.
> 
> In free software it is ideal to build everything from source.   I
> wonder how is such a package handled in Guix?   What is the strategy
> for bootstrapping?   Thanks

For circular dependencies our first attempt is to use a minimal variant
of the package that's missing features to build the full package. For
something like a language that depends on a working implementation of
itself we'll see if we can bootstrap it using either a previous version
of itself, a different implementation or a slimmed down version that has
enough working to be able to build itself.

Some notable examples are rust, bootstrapped from mrustc, and a chain of
rust compilers. Also go, bootstrapped from gccgo or go-1.4 (written in
C). One where this fails is GHC, where even going back to the early 90's
it was near impossible to find an implementation that didn't depend on a
previous version.

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Efraim Flashner   <efraim@flashner.co.il>   רנשלפ םירפא
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