[bug] gnu triplet for os=Linux arch=x86 is suboptimal

[t-8ch]

Environment Details (include every applicable attribute)

• Operating System+version: ArchLinux current
• Compiler+version: gcc 11.1.0
• Conan version: Current git head ( 1.24.0-1085-g106e54c9 )
• Python version: Python 3.10.1

Description

The GNU triplet that is created for arch=x86 on Linux is "x86-linux-gnu".
(This is only for Linux, other operating systems are translated as "i686" instead of "x86")

This causes issue when cross-compiling packages that are using gnulibs stack-direction.m4 (like m4 itself) because the "x86" machine is not recognized by that script.

I talked to the maintainer to gnulibs stack-direction.m4 and they recommended to instead use the more correct "i686" instead of "x86".

Looking at the source, I'm also wondering why there is a special case for Linux.

Steps to reproduce (Include if Applicable)

$ cat conanfile.txt 
[build_requires]
m4/1.4.19
$ conan install . -s arch=x86 --build m4
...
> source_subfolder/configure '--prefix=/home/t-8ch/.conan/data/m4/1.4.19/_/_/package/6173abd988ee2e3159da6cce836868055fdb1cb4' '--bindir=${prefix}/bin' '--sbindir=${prefix}/bin' '--libexecdir=${prefix}/bin' '--libdir=${prefix}/lib' '--includedir=${prefix}/include' '--oldincludedir=${prefix}/include' '--datarootdir=${prefix}/share' --build=x86_64-linux-gnu --host=x86-linux-gnu

...
checking for stack direction... unknown
...
compilation errors because the stack direction was not determined

[matlec]

Can confirm this issue in Conan 2.0.1. The wrong triplet prevents cross-compiling m4/1.4.19 to x86 on Linux. Any updates or work-arounds?

[matlec]

Replying to myself... to work-around this issue, we can override the GNU triplet in a profile for x86:

[conf]
tools.gnu:host_triplet=i686-linux-gnu

[memsharded]

Fixed in #15699, it will be in next 2.2 release