Bug#998224: hplip: HPLIP incorrectly links to obsolete or missing libhpdiscovery.so

[Troy Rollo <debian-bugs@troyrollo.com.au>]

Package: hplip
Severity: grave
Justification: renders package unusable

Dear Maintainer,

When building HPLIP, it incorrectly links to the already-installed
libhpdiscovery.so on the system when relinking .libs/libhpmud.so.0.0.6
If an old version that was linked to libnetsnmp.so.30 is found on the system,
libhpmud.so.0.0.6 is then dependent on that shared library, as is any other
shared library that links to libhpmud.so. The result is that HPLIP will not
run on buster or later because libnetsnmp.so.30 is not available.

This may be because libhpdiscovery.so never gets installed into
debian/tmp/usr/lib/x86_64-linux-gnu

The version of HPLIP in buster has this link to libnetsnmp.so.30

-- System Information:
Debian Release: 11.1
  APT prefers stable-security
  APT policy: (500, 'stable-security'), (500, 'stable-debug'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-9-amd64 (SMP w/8 CPU threads)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE=en_AU:en
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages hplip depends on:
ii  adduser                3.118
ii  cups                   2.3.3op2-3+deb11u1
ii  hplip-data             3.21.8+dfsg0-2
ii  libc6                  2.31-13+deb11u2
ii  libcups2               2.3.3op2-3+deb11u1
ii  libdbus-1-3            1.12.20-2
pn  libhpmud0              <none>
ii  libpython3.9           3.9.2-1
pn  libsane-hpaio          <none>
ii  libsane1               1.0.31-4.1
ii  lsb-base               11.1.0
pn  printer-driver-hpcups  <none>
ii  python3                3.9.2-3
ii  python3-dbus           1.2.16-5
ii  python3-gi             3.38.0-2
ii  python3-pexpect        4.8.0-2
ii  python3-pil            8.1.2+dfsg-0.3
ii  python3-reportlab      3.5.59-2
ii  wget                   1.21-1+b1
ii  xz-utils               5.2.5-2

Versions of packages hplip recommends:
ii  avahi-daemon                  0.8-5
ii  policykit-1                   0.105-31
ii  printer-driver-postscript-hp  3.21.8+dfsg0-2
ii  sane-utils                    1.0.31-4.1

Versions of packages hplip suggests:
pn  hplip-doc              <none>
pn  hplip-gui              <none>
ii  python3-notify2        0.3-4
ii  system-config-printer  1.5.14-1