Re: Can't build previous versions of Emacs?

[Ulrich Mueller]

>>>>> On Thu, 14 Jul 2022, Eric Abrahamsen wrote:

> Po Lu <luangruo@yahoo.com> writes:
>> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>> 
>>> Hi all,
>>> 
>>> I have the Emacs 25, 26 and 27 branches checked out in git worktrees,
>>> and I was going to build them to test some backwards compatibility. On a
>>> clean checkout, "make" failed for all three of them with this error:
>>> 
>>> sysdep.c:1795:22: error: variably modified ‘sigsegv_stack’ at file scope
>>> 1795 | static unsigned char sigsegv_stack[SIGSTKSZ];
>>> |                      ^~~~~~~~~~~~~
>>> make[2]: *** [Makefile:377: sysdep.o] Error 1
>>> make[2]: Leaving directory '/home/eric/dev/emacs-26/src'
>>> make[1]: *** [Makefile:421: src] Error 2
>>> make[1]: Leaving directory '/home/eric/dev/emacs-26'
>>> make: *** [Makefile:1107: bootstrap] Error 2
>>> 
>>> This is on Arch Linux, I can send the config.status file for any of the
>>> branches if that would help.
>> 
>> That's expected.  glibc recently changed in that SIGSTKSZ is now a call
>> to a function.  Emacs wasn't modified to be compatible with that until
>> 28.1.

> Thanks! That's good to know.

You can find patches for the SIGSTKSZ issue here:
https://gitweb.gentoo.org/proj/emacs-patches.git/tree/emacs

For example, for Emacs 27.2:
https://gitweb.gentoo.org/proj/emacs-patches.git/tree/emacs/27.2/02_all_glibc-2.34.patch