bug#37550: [core-updates] [PATCH] gnu: gcc: Fix i686-linux cross compiler.

[Jan Nieuwenhuizen]

Running

    ./pre-inst-env guix build --target=i686-unknown-linux-gnu hello

on core-updates (and similarly on core-updates-next) fails with

--8<---------------cut here---------------start------------->8---
checking for i686-unknown-linux-gnu-gcc... 
/tmp/guix-build-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.4.0.drv-0/build/./gcc/xgcc
 
-B/tmp/guix-build-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.4.0.drv-0/build/./gcc/
 
-B/gnu/store/p4x4981zidgq36rjkx0bxb466s81xk2z-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.4.0/i686-unknown-linux-gnu/bin/
 
-B/gnu/store/p4x4981zidgq36rjkx0bxb466s81xk2z-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.4.0/i686-unknown-linux-gnu/lib/
 -isystem 
/gnu/store/p4x4981zidgq36rjkx0bxb466s81xk2z-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.4.0/i686-unknown-linux-gnu/include
 -isystem 
/gnu/store/p4x4981zidgq36rjkx0bxb466s81xk2z-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.4.0/i686-unknown-linux-gnu/sys-include
   
checking for C compiler default output file name... 
configure: error: in 
`/tmp/guix-build-gcc-cross-sans-libc-i686-unknown-linux-gnu-7.4.0.drv-0/build/i686-unknown-linux-gnu/libmpx':
configure: error: C compiler cannot create executables
See `config.log' for more details.
--8<---------------cut here---------------end--------------->8---

The attached patch fixes this.

I stumbled upon this while working to fix #37549.  Where should this
patch land?

Greetings,
janneke

>From 522aac698a66ca8ab73ac3827c61cb65627684d3 Mon Sep 17 00:00:00 2001
From: Jan Nieuwenhuizen <address@hidden>
Date: Sun, 29 Sep 2019 13:08:01 +0200
Subject: [PATCH] gnu: gcc: Fix i686-linux cross compiler.

This resurrects

    ./pre-inst-env guix build --target=i686-unknown-linux-gnu hello

* gnu/packages/cross-base.scm (cross-gcc-arguments): Do not build libmpx;
does not cross-configure.
---
 gnu/packages/cross-base.scm | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gnu/packages/cross-base.scm b/gnu/packages/cross-base.scm
index 7108000f06..fab4636450 100644
--- a/gnu/packages/cross-base.scm
+++ b/gnu/packages/cross-base.scm
@@ -144,6 +144,7 @@ base compiler and using LIBC (which may be either a libc 
package or #f.)"
                                "--disable-libatomic"
                                "--disable-libmudflap"
                                "--disable-libgomp"
+                               "--disable-libmpx" ; C compiler cannot create 
executables
                                "--disable-libssp"
                                "--disable-libquadmath"
                                "--disable-decimal-float" ;would need libc
-- 
2.23.0

-- 
Jan Nieuwenhuizen <address@hidden> | GNU LilyPond http://lilypond.org
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