Setting up a Hurd build node

[Ricardo Wurmus <rekado@elephly.net>]

Hi Guix,

I just built Guix in a Debian GNU/Hurd VM and wanted to set it up as a
build node.  I applied a patch to use the i586-gnu bootstrap binaries
from my previous attempt in late 2018, which are published at
https://berlin.guixsd.org/guix/bootstrap/i586-gnu/20180908/.  These were
built with the old patched glibc 2.23.  (The patch to add the bootstrap
binaries is 3.5MB in size because it includes the statically linked
binaries, so I’m not attaching it here.)

Unfortunately, using the build users does not work:

--8<---------------cut here---------------start------------->8---
root@debian:~/guix-1.0.0# ./pre-inst-env guix-daemon --build-users-group=guixbuild --disable-chroot &
root@debian:~/guix-1.0.0# ./pre-inst-env guix build -S hello
madvise failed: Function not implemented
madvise failed: Function not implemented
madvise failed: Function not implemented
madvise failed: Function not implemented
substitute: madvise failed: Function not implemented
substitute: guix substitute: warning: ACL for archive imports seems to be uninitialized, substitutes may be unavailable
The following derivation will be built:
   /gnu/store/qihk8cf98xqc7q577wb2nc5axy2ryp8m-hello-2.10.tar.gz.drv
error: cannot kill processes for uid `999': Operation not permitted
guix build: error: cannot kill processes for uid `999': failed with exit code 1
--8<---------------cut here---------------end--------------->8---

Uid 999 belongs to guixbuilder01.  (The gid for the guixbuild group is
also 999.)

I also tried building “hello”, but I only get the message

    madvise failed: Function not implemented

printed endlessly.  (This is probably harmless, but nothing else
happens.)

--
Ricardo