Bug#923091: base-installer: Allow installing w/o the broken merged-usr-via-symlinks

[Guillem Jover <guillem@debian.org>]

Package: base-installer
Version: 1.187
Severity: wishlist

Hi!

The current base-installer uses the default debootstrap settings
which end up unconditionally installing systems with the
merged-usr-via-symlinks deployment method which is broken by design,
please see:

  <https://lists.debian.org/debian-devel/2019/02/msg00251.html>

I'm aware the original request to change the debootstrap default got
unfortunately moved to the tech-ctte. :(

But regardless of that outcome I'd like to request to have a way to
install using debootstrap's --no-merged-usr option, to not have to
install from stretch and then upgrade to buster, or having to drop into
a shell and do manual stuff from within the installer.

In addition it would be also nice if that option was passed whenever
/usr is not on its own partition, because then the properties from
the merged-/usr concept are not relevant anymore, but we get all the
downsides of the broken deployment method.

If this was to be applied for buster, I'd be happy to provide patches.

Otherwise I guess I might need to end up looking to generate
alternative netinst somewhere else or something. :(

Thanks,
Guillem