[bug] default GNU triplet of VIsual Studio is not understood by gnu autotools

[madebr]

When passing conan's default gnu triplet to a configure script, and using the MSVC toolchain,
configuration fails because autotools does not recognize these triplets.
(at least when they use autotools' AC_CANONICAL_HOST, AC_CANONICAL_BUILD or AC_CANONICAL_TARGET)
(See https://www.gnu.org/software/autoconf/manual/autoconf-2.65/html_node/Canonicalizing.html)

Conan generates x86_64-windows-msvc and i686-windows-msvc respectively 64- and 32-bit Visual Studio builds.
GNU's config.guess guesses x86_64-pc-mingw64 and x86_64-pc-mingw32

While conan's generated triplet is more correct, it is not understood by most autotools project.

A workaround is to not pass gnu triplets when building using Visual Studio.
This can be achieved by passing host=False, build=False to autotools.configure(...).

I've opened this issue, to gather feedback on this issue.

Environment Details (include every applicable attribute)

• Operating System+version: Windows 10
• Compiler+version: Visual Studio 2017

Steps to reproduce (Include if Applicable)

Build a autotools project.
Following issues show the problem (and include logs):

• [package] m4/1.4.18 won't build on x86 conan-center-index#2183
• [package] bison/3.5.3: Cannot build on x86, doesn't seem to understand canonical names or something conan-center-index#2300

[memsharded]

While conan's generated triplet is more correct, it is not understood by most autotools project.

I am not fully sure about the best approach, but from my limited understanding, it seems that would be a limitation or flaw in the autotools code. Then, wouldn't it be the best to patch the autotools code? I know it might be challenging to do this correctly, but conceptually seems the right thing to do.

[madebr]

Then, wouldn't it be the best to patch the autotools code? I know it might be challenging to do this correctly, but conceptually seems the right thing to do.

That's correct.
Autotools' detection code lives here: https://savannah.gnu.org/projects/config/
I've added a CCI recipe here: conan-io/conan-center-index#2302