Subject: bug#62231: closed (Re: bug#62231: Chez Scheme for Racket build on aarch64 (patch attached))

From: [email-masked] (GNU bug Tracking System)
Date: Sun, 26 Mar 2023 14:27:02 +0000

Your bug report

#62231: Chez Scheme for Racket build on aarch64 (patch attached)

which was filed against the guix-patches package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
62231: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=62231
GNU Bug Tracking System
Contact [email-masked] with problems

Subject: Re: bug#62231: Chez Scheme for Racket build on aarch64 (patch attached)
From: Ludovic Courtès <[email-masked]>
To: Tim Johann <[email-masked]>
Cc: [email-masked], Philip McGrath <[email-masked]>
Date: Sun, 26 Mar 2023 16:26:33 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

Hi,

Tim Johann <[email-masked]> skribis:

> commit e3c514db745d48e5ef7f7abb7b45037341298b17
> Author: Tim Johann <[email-masked]>
> Date:   Fri Mar 24 21:09:52 2023 +0100
>
>     gnu: chez-scheme-for-racket-bootstrap-bootfiles: change for aarch64.
>     
>     * gnu/packages/chez.scm (chez-scheme-for-racket-bootstrap-bootfiles):
>       Temporary change for build on aarch64, making racket available on aarch64.
>       Architecture autodetect in rktboot only addresses x86 archs, so far.
>       This work-around sets the architecture, looked up in translation table,
>       explicitly.  The long term solution should be to fix rktboot to include
>       other natively supported architectures in the autodetect mechanism.
>         cf. https://github.com/racket/racket/issues/3948
>       [arguments] use --machine even when architecture is supported by Racket's
>       fork of ChezScheme.

Applied!

Thank you Tim, and thanks Philip for reviewing.

Tim: please use ‘git format-patch’ in the future; the format here cannot
be ingested as-is by ‘git am’.

Ludo’.

Subject: Chez Scheme for Racket build on aarch64 (patch attached)
From: Tim Johann <[email-masked]>
To: [email-masked]
Date: Fri, 17 Mar 2023 00:23:46 +0100
List-Id: <debbugs-submit.debbugs.gnu.org>

Hi Guix Team,

tl;dr;

The recipe for package 'chez-scheme-for-racket-bootstrap-bootfiles' (a
dependency for racket-8.*) needs to use the --machine flag to build on aarch64
(and possibly also ppc32, the other non-x86 architectures supported by the
Racket fork of Chez Scheme).  I therefore suggest the attached patch to make
building and using Racket possible on aarch64 Guix.

End of tl;dr;

A few weeks ago I wanted to use Racket on Guix on aarch64, but was made aware,
that Racket was not available as a substitute and it did not build.  On the
other hand, recent versions of Racket were available on Raspberry Pi OS which is
explicitly running on aarch64.  The machine I am running Guix on actually is a
Raspberry Pi 4B.

So, I dug deeper to find that the problem is that the package
  chez-scheme-for-racket-bootstrap-bootfiles
fails with the error
,----
|   string-append: contract violation
|   expected: string?
|   given: #f
|   argument position: 1st
|   other arguments...:
|    ".def"
|   context...:
|    /tmp/guix-build-chez-scheme-for-racket-bootstrap-bootfiles-9.9.9-pre-release.14.drv-0/source/racket/src/rktboot/machine-def.rkt:6:0: open-file-with-machine.def-redirect
| error: in phase 'build': uncaught exception:
| %exception #<&invoke-error program: "/gnu/store/0n4skakcg05bbq9sq7g00j2zm25xh4wa-racket-vm-bc-8.8/opt/racket-vm/bin/racket" arguments: ("../rktboot/main.rkt") exit-status: 1 term-signal: #f stop-signal: #f> 
| phase `build' failed after 14.3 seconds
| command "/gnu/store/0n4skakcg05bbq9sq7g00j2zm25xh4wa-racket-vm-bc-8.8/opt/racket-vm/bin/racket" "../rktboot/main.rkt" failed with status 1
| builder for `/gnu/store/d04mbj02vzjv0ljcqy2lxs33scz7kjz0-chez-scheme-for-racket-bootstrap-bootfiles-9.9.9-pre-release.14.drv' failed with exit code 1
| @ build-failed /gnu/store/d04mbj02vzjv0ljcqy2lxs33scz7kjz0-chez-scheme-for-racket-bootstrap-bootfiles-9.9.9-pre-release.14.drv - 1 builder for `/gnu/store/d04mbj02vzjv0ljcqy2lxs33scz7kjz0-chez-scheme-for-racket-bootstrap-bootfiles-9.9.9-pre-release.14.drv' failed with exit code 1
`----
(see, e.g. the build [442314 on ci.guix.gnu.org]).

The Racket fork of Chez is natively supported on aarch64, which is supported by
comments in module (gnu packages chez), so I went on to find that machine
architecture is communicated in the build process by setting the environment
variable MACH.  I haven't looked to verify this, but it seems that this
environment variable is normally set to a guessed value by the zuo build process
(zuo for 'make' in Mandarin?).

The Guix build recipe for chez-scheme-for-racket-bootstrap-bootfiles, though, is
not configuring the whole downloaded racket source package but takes the
shortcut of just building ChezScheme in the subdirectory
  racket/src/ChezScheme
using the Racket utility
  ../rktboot/main.rkt
This script would actually accept the flag '--machine' and would set the
environment variable MACH to the value of the argument following the flag.

The problem is that in the case of aarch64 the recipe would not set the flag.
In the recipe for chez-scheme-for-racket-bootstrap-bootfiles in module (gnu
packages chez), we find the lines
,----
| #~(invoke
|    (search-input-file (or native-inputs inputs)
|                       "/opt/racket-vm/bin/racket")
|    "../rktboot/main.rkt"
|    #$@(if (racket-cs-native-supported-system?)
|           #~()
|           (let ((m (nix-system->pbarch-machine-type)))
|             #~("--machine" #$m)))))))))))))
`----
and, since `(racket-cs-native-supported-system?)' returns `tarm64le', the first
branch of the if expression is taken, ommitting the flag.

I suggest to change the above code to the following:
,----
| #~(invoke
|    (search-input-file (or native-inputs inputs)
|                       "/opt/racket-vm/bin/racket")
|    "../rktboot/main.rkt"
|    #$@(let ((m (or (racket-cs-native-supported-system?)
|                    (nix-system->pbarch-machine-type))))
|         #~("--machine" #$m))))))))))))
`----
which sets the flag for natively supported architectures and those supported by
portable bytecode.

The package (and subsequently Racket) builds on aarch64, the build on x86_64
seems to be unaffected.

It is a simple change which would make a huge difference for Guix users who want
to be able to play with Racket on an aarch64 machine.

Cheers

Tim

Lá Fhéile Pádraig sona dhaoibh!

[442314 on ci.guix.gnu.org] <https://ci.guix.gnu.org/build/442314/log/raw>
commit f8d7b06a92b3839da1908837ac81ab6295626cf5
Author: Tim Johann <[email-masked]>
Date:   Thu Mar 16 18:53:13 2023 +0100

    gnu: chez-scheme-for-racket-bootstrap-bootfiles: change for aarch64.
    
    * gnu/packages/chez.scm (chez-scheme-for-racket-bootstrap-bootfiles):
    change for build on aarch64, making racket available on aarch64.
    [arguments] use --machine even when architecture is supported by Racket's
    fork of ChezScheme.

diff --git a/gnu/packages/chez.scm b/gnu/packages/chez.scm
index c6420a980e..bc709917c2 100644
--- a/gnu/packages/chez.scm
+++ b/gnu/packages/chez.scm
@@ -692,10 +692,9 @@ (define-public chez-scheme-for-racket-bootstrap-bootfiles
                          (search-input-file (or native-inputs inputs)
                                             "/opt/racket-vm/bin/racket")
                          "../rktboot/main.rkt"
-                         #$@(if (racket-cs-native-supported-system?)
-                                #~()
-                                (let ((m (nix-system->pbarch-machine-type)))
-                                  #~("--machine" #$m)))))))))))))
+                         #$@(let ((m (or (racket-cs-native-supported-system?)
+                                         (nix-system->pbarch-machine-type))))
+                              #~("--machine" #$m))))))))))))
     (supported-systems
      (package-supported-systems chez-scheme-for-racket))
     (home-page "https://github.com/racket/ChezScheme")