Bug#941937: apt: Unexpected linkage dependency on libsystemd

[Andreas Messer <andi@bastelmap.de>]

Package: apt
Version: 1.8.2
Severity: normal

I observed a linkage dependency on libsystemd. This was unexpected for me
since I wouldn't expect a package manager depend on it. A package manager should
be as lean as possible.

Having reviewed the code, the only function using libsystemd is used to talk on dbus 
to inhibit system shutdown. Something which will work for systemd only.

Would it make sense to use dlopen() to dynamically load libsystemd when needed
and avoid the hard dependency on libsystemd? If systemd is installed, libsystemd
will be available anyways.

-- Package-specific info:

-- (no /etc/apt/preferences present) --
-- (/etc/apt/preferences.d/avoid-systemd present, but not submitted) --
-- (/etc/apt/sources.list present, but not submitted) --
-- (/etc/apt/sources.list.d/devuan.list present, but not submitted) --


-- System Information:
Debian Release: 10.0
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-6-amd64 (SMP w/2 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=de_DE.UTF-8 (charmap=UTF-8), LANGUAGE=de_DE.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)
LSM: AppArmor: enabled

Versions of packages apt depends on:
ii  adduser                 3.118
ii  debian-archive-keyring  2019.1
ii  gpgv                    2.2.12-1+deb10u1
ii  libapt-pkg5.0           1.8.2
ii  libc6                   2.28-10
ii  libgcc1                 1:8.3.0-6
ii  libgnutls30             3.6.7-4
ii  libseccomp2             2.3.3-4
ii  libstdc++6              8.3.0-6

Versions of packages apt recommends:
ii  ca-certificates  20190110

Versions of packages apt suggests:
pn  apt-doc         <none>
ii  aptitude        0.8.11-7
ii  dpkg-dev        1.19.7
ii  gnupg           2.2.12-1+deb10u1
ii  powermgmt-base  1.34
ii  synaptic        0.84.6

-- no debconf information

-- 
gnuPG keyid: 8C2BAF51
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