emacs24/25 FTBFS since a long time on GNU/Hurd

[Svante Signell <svante.signell@gmail.com>]

Hello,

I'm not subscribed to emacs-devel, but hope to get this mail through anyway.

Since a long time emacs FTBFS due to unknown reasons. The latest version
building was Debian 24.5+1-5, from 27 Nov 2015. Even before successful builds
were by pure luck. One suspicious issue is that emacs use sbrk() for memory
allocation, right? Notably sbrk() is not fool-proof as implemented for Hurd in
glibc. Use of sbrk is found in files alloc.c, unexelf.c and gmalloc.c, which are
all compiled. Avoiding compilation of ralloc.c with 0001-Default-REL_ALLOC-to-
no.patch did not improve the situation.

First time I compiled emacs 25.1 from upstream it passed, second time not.
Compiling Debian versions almost always fail. Moslty the build fails with temacs
failing to execute: Killed. In my opionion it's a real loss not to gave a modern
version of emacs25 available for use in GNU/Hurd (not everybody use vi).

Do anybody of you have an idea on how to solve this problem? Are there patches
available already to try with?

Thanks in advance :)