This bug was fixed in the package mdadm - 4.1-8ubuntu1

---------------
mdadm (4.1-8ubuntu1) hirsute; urgency=low

  * Merge from Debian unstable.  Remaining changes:
    - Ship finalrd hook.
    - Do not install mdadm-shutdown.service on Ubuntu.
    - Drop broken and unused init scripts in favor of native systemd units,
      which can cause failure to reconfigure mdadm package under certain
      confiment types.
    - Drop /etc/cron.d/mdadm and migrate to systemd mdcheck_start|continue
      timer units.
    - Drop /etc/cron.daily/mdadm and migrate to system mdmonitor-oneshot
      timer unit.
    - mdcheck_start.timer configures the mdcheck on a first sunday of the
      month, with a randomized start delay of up to 24h, and runs for at
      most 6h. mdcheck_continue.timer kicks off daily, with a randomized
      start delay of up to 12h, and continues mdcheck for at most 6h.
    - mdmonitor-oneshot.timer runs daily, with a randomized start delay of
      up to 24h.
    - One can use systemd drop-ins to change .timer units timings, set
      environmental variables to decrease/increase the length of checking,
      or start the checks by hand. Previously used checkarray is still
      available, albeit not used by timer units.
    - Above ensures that previous daily / monthly checks are performed, but
      are randomized, such that performance is not as impacted across a
      cluster of machines.
    - Honor the debconf daily autoscan setting in the systemd timer.
    - d/p/mdcheck-fix-empty-spaces-in-timer-unit-files.patch:
      - The spaces were causing a FTBFS situation, triggered by
        dh_installsystemd not finding units.
    - d/p/mdcheck-when-mdcheck-start-is-enabled-mdcheck-continue-too.patch:
      - When mdcheck_start is enabled, enable mdcheck_continue too.
    - d/p/mdcheck-log-when-done.patch:
      - Make sure mdcheck logs the completion too, so that
      it can be determined how long the raid check took.

  * Also fix up whitespace in systemd/mdmonitor-oneshot.timer.
  * Cherrypick upstream fix to allow assembling dirty degrated IMSM raid
    arrays with --force flag. LP: #1894792

mdadm (4.1-8) unstable; urgency=medium

  * Comprehensive FAQ improvements and amendments.(Closes: #715387)
  * Update Finnish debconf translation. (Closes: #972143)
  * Update Portuguese debconf translation. (Closes: #971941)
  * Update Basque debconf translation.

mdadm (4.1-7) unstable; urgency=medium

  * Look for md device in /dev/md and exit gracefully on failure.
    (Closes: #958060, #970329)
  * Update Spanish, Italian, Slovak and Russian debconf translations.
    (Closes: #970381, #970568, #970578)

mdadm (4.1-6) unstable; urgency=medium

  * Install misc/mdcheck; thanks Richard Laager. (Closes: #960132)
  * Update French, Dutch and German debconf translations. (Closes: #935184,
    #940851, #956350)
  * Bring command-line help in line with manual page. (Closes: #932791)
  * Fix spelling and groff macro issues in manual pages. (Closes: #915182,
    #916946, #962946)
  * Explain 'max' keyword in command-line option --size. (Closes: #933773)
  * Patch d/README.recipes for clarity. (Closes: #619043)
  * Enable autopkgtest for installed version. Requires isolation-machine,
    untested. (Closes: #872118)
  * Adopt package. (Closes: #924367)
  * Turn on hardening.
  * Avoid a race condition in d/mdadm-shutdown.service.
  * Implement missing status option in /etc/init.d/mdadm-waitidle.
  * Add missing Documentation keys to several service files.
  * Upgrade debhelper compat to 13; use new prerequisite style.
  * Set Rules-Requires-Root: no.
  * Bump Standards-Version to 4.5.0.
  * Convert copyright to DEP-5 machine-readable format.
  * Host Vcs on salsa.d.o.
  * Adopt DEP-14 branch naming in Vcs-Git
  * Enable standard Salsa CI pipeline.
  * Fix typos in executables.
  * Explain that --name does not work in Grow mode.
  * Convert international debconf translations to UTF-8.
  * Capitalize first word in package synopsis.
  * Add Lintian overrides for tags that may not be appropriate.

 -- Dimitri John Ledkov <email address hidden>  Mon, 26 Oct 2020 12:15:40 +0000