bug#43369: Emacs fails to configure on ARM Macs

[Lars Ingebrigtsen]

Itai Seggev <is+apple@cs.hmc.edu> writes:

> Out of the box, that is, using master (specifically SHA 18f390af8f11d24c)
> ./configure fails when building on an ARM Mac.  The problem is that the
> canonical triple has the form aarch64-apple-darwin20.1.0, but configure.ac is
> looking for a triple of the form arm-*.
>
> After changing arm to aarach64, I was able to build successfully both a Cocoa
> and X11 versions (the latter pretty minimal, given that toolkits are still
> being ported).
>
> Here is the diff for ease of refence:
>
> diff --git a/configure.ac b/configure.ac
> index 33948fd776..40b63905ab 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -724,7 +724,7 @@ AC_DEFUN
>    *-apple-darwin* )
>      case "${canonical}" in
>        *-apple-darwin[0-9].*) unported=yes ;;
> -      i[3456]86-* | x86_64-* | arm-* )  ;;
> +      i[3456]86-* | x86_64-* | aarch64-* )  ;;

The arm-* bit was added recently to Emacs, from a two-year-old patch:

commit 4cba236749aafade7bd88cf2a10be48f44983faa
Author:     Roland Kaufmann <rlndkfmn+emacs@gmail.com>
AuthorDate: Thu Dec 27 15:51:49 2018 +0100
Commit:     Alan Third <alan@idiocy.org>
CommitDate: Sat Aug 15 17:06:31 2020 +0100

    Allow build configuration on Apple ARM devices (bug#41994)
    
So it sounds like arm-* was in use, and it's now aarch64-*?  In which
case adding the latter, instead of altering it, is the right change here?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no