Add ruby-for-crystal.

Hi Guix,

We've (Ryan, David, Raghav, and others) started packaging crystal for guix: https://crystal-lang.org/

This patch adds an old version of ruby that is required by the crystal language bootstrap process. This is related to 49142.

This was an effort of the volunteers at the last guix packaging meetup hosted by LibreMiami.

Here are some notes, questions, and a list of dependencies regarding what is needed to finish a properly bootstraped crystal package:

We are trying to recreate this bootstrapping process in guix:

There are 160 stages!

Some questions extracted from our notes follow:

Is it preferable to have 160 bootstrap packages, one for each stage, or one big bootstrap package with 160 build-* stages, or somewhere inbetween?

Each stage needs a different checkout of the git repository - can we preserve info in .git such that we can checkout again during the build, or do we want to have each checkout be an independent input to the package?

How best can we use Guile macros to clean up the large amount of code implied by executing 160 stages of bootstrap logic?

best regards,

jgart

jgart via Guix-patches via schreef op ma 21-06-2021 om 16:19 [+0000]:

Definitely 160 separate bootstrap packages I'd say.

Though the first 159 wouldn't be exported and would be hidden.

Because:

(1) presumably, building all these different versions of crystal

would take a lot of time

(2) if the build process OOMS, if there is a build failure at some

stage, the user cancelled the build, and retried,

then ideally Guix wouldn't start rebuilding the previous stages

(3) so, 160 separate packages.

There doesn't seem to be much reason to use

macro's here (except 'package' & 'define' itself)

Basically, you'd do something similar to what's already done

for Rust:

(define* (crystal-bootstrapped-package base-crystal version checksum commit)

"Bootstrap crystal VERSION with source checksum CHECKSUM and git commit COMMIT

using BASE-CRYSTAL"

(package

(inherit base-crystal)

(version version)

(source

(origin

(inherit (package-source base-crystal))

(commit commit)

(sha256 (base32 checksum))))))

To start the process,

define an initial version crystal-stage1 like you'd do for any other package.

Then, for each N+1, define

(define crystal-N+1 (crystal-bootstrapped-package crystal-N VERSION CHECKSUM COMMIT))

Some crystals probably need somewhat different inputs, or require some fudging

in phases, so you might to occasionally modify the resulting package a little:

(define crystal-N+1

(package

(inherit crystal-N)

(inputs `(("stuff" ,libstuff)

,@(package-inputs crystal-N)))

And export the final version:

;; Don't forget to remove the 'hiddenness' from crystal-160!

(define-export crystal crystal-160)

The .git directory isn't bit-for-bit reproducible

(think different versions of git, different versions of compression

libraries, different parallelism levels, etc. causing a slightly

different pack), so no.

Also, falling back to Software Heritage wouldn't work.

If you'll be using the 'crystal-bootstrapped-package' from above,

then you'll automatically get independent inputs.

Greetings,

Maxime.

Hello,

"jgart" <jgart@dismail.de> writes:

Since the crystal-lang patches haven't landed in more than a year,

I think it's safer to punt on this.

Closing.

Thanks!

Maxim

On Wed, 28 Sep 2022 14:36:12 -0400 Maxim Cournoyer <maxim.cournoyer@gmail.com> wrote:

makes sense!

...for now ;)

thnx for closing