Comment 1 for bug 1251228

This bug was fixed in the package unattended-upgrades - 1.18

---------------
unattended-upgrades (1.18) experimental; urgency=medium

  [ louib ]
  * Update blacklist translations
  * Fix syntax in template conf files

  [ Balint Reczey ]
  * Keep mypy 0.761 happy
  * test: Create empty dirs to save kept packages list to them
  * Log explanation about kept back packages (LP: #1850964)
    (Closes: #945837, #903875)
  * Use GitHub Actions for CI instead of Travis.
    Run tests in Ubuntu Focal release because older releases don't have the
    needed python-apt version.
  * debian/tests/common-functions: Use backported python-apt from a PPA on Eoan
  * debian/tests: Skip upgrade-between-snapshots test.
    Python-apt's version is sid is too low for unattended-upgrades to work.
  * Use apt_pkg.Hashes instead of deprecated apt_pkg.md5sum()
  * autopkgtest: Skip upgrate-all-security in sid because buster can't be tested
  * Make allowed_origins, blacklist and whitelist attributes of
    UnattendedUpgradesCache
  * Make strict_whitelist attribute of UnattendedUpgradesCache
  * Apply pinning to disable not allowed origins and honor blacklist/whitelist.
    This makes candidate adjustments obsolete, since apt's resolver would pick
    candidates only from allowed origins by itself unless local pinning
    configuration overrides that.
  * Rely fully on pinning to disable allowed origins and stop adjusting
    candidates.
  * Drop Unattended-Upgrade::Allow-downgrade since now pinning is honored and
    downgrades are allowed for package versions with priority >= 1000.
    (Closes: #905877, #919046, #768087, #946491) (LP: #1251228, #1434115)
  * Don't ignore allowed origin when the package's priority is < 100.
    This used to be the way of honoring the priority, but now this special case
    prevents the package from showing up as a package kept back.
  * Assume frontend locking to be supported.
    Python3-apt (>= 1.9.6~) is required which supports the frontend locking API

 -- Balint Reczey <email address hidden> Tue, 25 Feb 2020 19:28:13 +0100