Bug#913061: systemd: stop shipping /bin/systemd

[Ansgar]

Ben Hutchings writes:
> On Wed, 2019-09-11 at 19:20 +0200, Ansgar wrote:
>> would it be possible to add a fallback to try /lib/systemd/systemd if
>> the user provided init=/bin/systemd and the file no longer exists?
>> 
>> I would like systemd to stop shipping the /bin/systemd symlink as this
>> should not be run by users, however it was suggested to use
>> init=/bin/systemd for testing purposes in the past (see below).  So just
>> removing the symlink might make some systems unbootable.
>
> I don't think it's appropriate for the initramfs to do this sort of
> magic.  Even if they did, this wouldn't cover systems using a custom
> kernel that doesn't need an initramfs.
>
> I think that a better way to handle this would be for systemd itself to
> warn on upgrade if /proc/cmdline contains init=/bin/systemd.

The problem is that many people don't read warning or don't react on
them right away.  So I would prefer if we had an additional safety net.
If this wouldn't result in unbootable systems, I agree that a warning
would be sufficient.

Ansgar