bug#42327: Offload build to Childhurd selects linux-libre-headers

[Jan Nieuwenhuizen]

Hi!

The offload build works, yay!...all the way up to

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix build --system=i586-gnu \
   -e '(@@ (gnu packages commencement) glibc-final-with-bootstrap-bash)'
/gnu/store/cah6lzl8cxdhfink3a1ij0m1p5vk66kw-glibc-intermediate-2.31-debug
/gnu/store/i7l6dnq6br3jg5qzhfssrp11mg499d2b-glibc-intermediate-2.31
/gnu/store/lr2ymww5imjl3hxrzyc7dmsadw7dxbdh-glibc-intermediate-2.31-static
--8<---------------cut here---------------end--------------->8---

With static-bash-for-glibc, however, it goes off track

--8<---------------cut here---------------start------------->8---
$ ./pre-inst-env guix build --system=i586-gnu \
   -e '(@@ (gnu packages commencement) static-bash-for-glibc)'
The following derivations will be built:
   /gnu/store/gv40jpz4g0hbia28wa6d50z9x6ncgdlh-bash-static-5.0.16.drv
   /gnu/store/apj2ihazv6x3anhvfvmmqrkyak05p9yc-gcc-cross-boot0-wrapped-7.5.0.drv
   /gnu/store/yfpy5b3xqkarxchyhi339fw2ldwczj1d-linux-libre-headers-5.4.20.drv
--8<---------------cut here---------------end--------------->8---

...oops!  Note that a native build on the Childhurd works all the way up
to "hello".

The "glibc-final-with-bootstrap-bash" has a propagated-inputs that looks
like this

--8<---------------cut here---------------start------------->8---
(define* (kernel-headers-boot0 #:optional (system (%current-system)))
  (match system
    ("i586-gnu" hurd-core-headers-boot0)
    (_ linux-libre-headers-boot0)))

(define glibc-final-with-bootstrap-bash
   [..]
   (propagated-inputs `(("kernel-headers" ,(kernel-headers-boot0))))
   [..])
--8<---------------cut here---------------end--------------->8---

In KERNEL-HEADERS-BOOT0, SYSTEM is "x86_64-linux".  Passing SYSTEM from
a LET-SYSTEM clause (see attached patch) seems to fix this...but i'm
afraid that triggers a world rebuild.  Our offload Childhurds can only
run master, right?  Is there any way around this?  Thoughts?

Greetings,
--a-mildly-disappointed--
Janneke

>From 28bdd162e5430517df3957b8454c49d037d684ba Mon Sep 17 00:00:00 2001
From: "Jan (janneke) Nieuwenhuizen" <janneke@gnu.org>
Date: Sat, 11 Jul 2020 22:44:39 +0200
Subject: [PATCH] commencement: glibc-final-with-bootstrap-bash: Fix
 kernel-headers.
Content-Transfer-Encoding: 8bit
Content-Type: text/plain; charset=UTF-8

* gnu/packages/commencement.scm (glibc-final-with-bootstrap-bash)
[propagated-inputs]: Use let-system to pass correct system
kernel-headers-boot0.
---
 gnu/packages/commencement.scm | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/gnu/packages/commencement.scm b/gnu/packages/commencement.scm
index d0393ebe25..518ffd0bd8 100644
--- a/gnu/packages/commencement.scm
+++ b/gnu/packages/commencement.scm
@@ -49,6 +49,7 @@
   #:use-module (gnu packages pkg-config)
   #:use-module (gnu packages rsync)
   #:use-module (gnu packages xml)
+  #:use-module (guix gexp)
   #:use-module (guix packages)
   #:use-module (guix download)
   #:use-module (guix build-system gnu)
@@ -3298,7 +3299,8 @@ memoized as a function of '%current-system'."
                                      "export CPATH\n"
                                      all "\n")))
                    #t)))))))
-    (propagated-inputs `(("kernel-headers" ,(kernel-headers-boot0))))
+    (propagated-inputs `(("kernel-headers" ,(let-system (system target)
+                                              (kernel-headers-boot0 system)))))
     (native-inputs
      `(("bison" ,bison-boot0)
        ("texinfo" ,texinfo-boot0)
-- 
Jan Nieuwenhuizen <janneke@gnu.org> | GNU LilyPond http://lilypond.org
Freelance IT http://JoyofSource.com | Avatar® http://AvatarAcademy.com

-- 
Jan Nieuwenhuizen <janneke@gnu.org> | GNU LilyPond http://lilypond.org
Freelance IT http://JoyofSource.com | Avatar® http://AvatarAcademy.com