On Wed, Jul 25, 2018 at 10:25:32PM +0100, Simon Hobson wrote:
> KatolaZ <katolaz@???> wrote:
>
> > Replace 'links2' with 'openssh-server' and 'libfbdirect' with
> > 'libsystemd0', and you should see what I mean. Most of the De??an
> > installations actually have tons of libraries that are never used, or
> > are just used to probe for a certain functionality that is not
> > available. This happens all the time, under the hood.
>
> Well yyeeessss, and no.
> AIUI it is **possible** to write your program with functionality along the lines of :
> - test if libx is available

How do you do that at runtime, exactly, and in a portable way? The
only way would be using libdl, but that's a pretty shitty way of using
libraries, if you have to use that all the time.

> - if so
> -- load libx
> -- call function y to see if facility z is available
>
>
> But that's a fair bit more work than just :
> (assume libx is present, link to libx when building binary)
> - call function y and let the system take care of loading libx
>
> Certainly when I raised a bug report against clamav the response was a "quite emphatic" "that's how it works, if libsystemd0 isn't present then your system is broken because that's now Debian policy". It's clear that libsystemd linkage is here to stay in Debian packaging, and it's equally clear that rebuilding **LOTS** of packages *just* to remove that one call to find out that systemd isn't present would not be a good use of the limited developer time & skills available.

The main problem is that those packages need to be maintained, and not
just stripped of the libsystemd0 dependency once, and then forgotten,
which is what happened with most of the Jessie packages that were
forked for that reason.

The medium-term plan is to replace libsystemd0 with a libnosystemd
which Provides: libsystemd0 and noops everything, with the possibility
of shelling-out some actions, if the admin wants so. We will get
there.

My2Cents

KatolaZ

-- 
[ ~.,_  Enzo Nicosia aka KatolaZ - Devuan -- Freaknet Medialab  ]  
[     "+.  katolaz [at] freaknet.org --- katolaz [at] yahoo.it  ]
[       @)   http://kalos.mine.nu ---  Devuan GNU + Linux User  ]
[     @@)  http://maths.qmul.ac.uk/~vnicosia --  GPG: 0B5F062F  ] 
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