bug#33639: ISO installer image is broken on i686

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

just to report that i did not forget this problem:

I have now a qemu-system-i386 VM with Debian GNU/Linux from
debian-9.6.0-i386-netinst.iso without desktop environment and reachable
via SSH. Very minimal. (I only did "apt-get install build-essential" to
feel not lonely without C compiler and friends.)

Then i followed the instructions of
  https://www.gnu.org/software/guix/manual/en/html_node/Binary-Installation.html
with
  https://alpha.gnu.org/gnu/guix/guix-binary-0.16.0.i686-linux.tar.xz
  https://alpha.gnu.org/gnu/guix/guix-binary-0.16.0.i686-linux.tar.xz.sig
up to step 7 ("guix archive --authorize ...").

Then i made the mistake to do the proposed

  guix package -i hello

It downloads and builds and blows away the free space on the virtual 8 GB
disk ... /gnu is growing steadily and /tmp breathes between 50 MB and 2 GB.
I abort this after 100 minutes before the virtual disk gets too full and
my CPU melts.

"guix pull" happily begins to build that gcc-5.5.0 which is too much for my
feeble VM.

Back to step 0 ("rm -r /gnu /var/guix") and again to step 7.
(A small fight starts between me and systemd, to get guix-daemon running.
 "start" did not help. It had to be "restart".)

Then

  # guix system disk-image --file-system-type=iso9660 \
  >   -s i686-linux \
  >   ~/.config/guix/current/share/guile/site/2.2/gnu/system/install.scm

and the activities to build the world start again. Extra verbose.
This time i abort after 30 minutes.

Everything i do ends up in enormous production of gcc-5.5.0 related
software.

-------------------------------------------------------------------------

So for xorriso and a 32-bit system:

  # apt-get install xorriso
  ...
  # xorriso -version
  xorriso 1.4.6 : RockRidge filesystem manipulator, libburnia project.
  ...

I try what happens if i pack up the /gnu tree:

  # xorriso -as mkisofs -o /tmp/test.iso -J /gnu
  ...
  ISO image produced: 643046 sectors
  Written to medium : 643046 sectors at LBA 0
  Writing to 'stdio:/tmp/test.iso' completed successfully.

Inspection shows that the size ideas of xorriso match the image file size:

  # xorriso -indev /tmp/test.iso
  ... no warning about size mismatch ...
  Media summary: 1 session, 643046 data blocks, 1256m data, 3234m free

  # ls -l /tmp/test.iso
  -rw-r--r-- 1 root root 1316958208 Dec 15 19:17 /tmp/test.iso

  # expr 1316958208 / 2048
  643046

Now with GNU xorriso 1.5.0:

  $ wget https://www.gnu.org/software/xorriso/xorriso-1.5.0.tar.gz
  ...
  $ tar xzf xorriso-1.5.0.tar.gz
  $ cd xorriso-1.5.0
  $ ./configure && make
  ...
  $ xorriso/xorriso -version
  GNU xorriso 1.5.0 : RockRidge filesystem manipulator, libburnia project.
  ...

  # rm /tmp/test.iso
  # xorriso/xorriso -as mkisofs -o /tmp/test.iso -J /gnu
  GNU xorriso 1.5.0 : RockRidge filesystem manipulator, libburnia project.
  ...
  ISO image produced: 643046 sectors
  Written to medium : 643046 sectors at LBA 0
  ...

Inspection yields the same result. No truncation.

-------------------------------------------------------------------------

If i shall try again with "guix system disk-image", then i need more
guidance. E.g. about the required disk size and ways to curb the build
effort.


Have a nice day :)

Thomas