package sendmail-bin 8.15.2-12 failed to install/upgrade: installed sendmail-bin package post-installation script subprocess returned error exit status 2

Status changed to 'Confirmed' because the bug affects multiple users.

Happened for me when trying to upgrade from 18.10.
When trying to configure the sendmail paclage, exit status 2 is returned.
Tried with linux 5.0.0-13.

Looks to me like it's a problem with the init.d script. (See the attached "DpkgTerminalLog.txt" file:

start-stop-daemon: matching only on non-root pidfile /var/run/sendmail/mta/sendmail.pid is insecure

Some other packages had similar problems (exim, amavis_d), but I'm not clear on how to correct this problem (despite having tried several ways).

And I'm stuck. Cannot complete a reinstallation of sendmail, cannot remove or purge it either. I get the above message (matching...is insecure) every time.

Does someone have a workaround?

My workaround was the following:

sudo su -
service sendmail stop
apt install -f

This worked for me. :)

What worked for me was killing any running sendmail processes (stopping the service did not do this) and then updating worked with no noticeable issues.
The only thing I see is sm-mta warnings that "My unqualified host name (HOSTNAME) unknown", which for me is a non-issue since this box is on my home network with no domain.

Just adding another voice to this thread. I had the same problem during the upgrade. The failure for sendmail-bin to properly configure caused the sensible-mta, dovecot-core and inn2 packages to all fail to properly update due to dependency problems. Thanks to Mirko above, who suggested a solution. Stopping the sendmail service and running "apt install -f" allowed the configuration to complete.

In case it is any help, here are the relevant log messages:

Messages from /var/log/dist-upgrade/main.log:

ERROR got an error from dpkg for pkg: 'sendmail-bin': 'installed sendmail-bin
    package post-installation script subprocess returned error exit status 2'
2019-07-07 22:44:50,515 DEBUG running apport_pkgfailure() sendmail-bin:
    installed sendmail-bin package post-installation script subprocess
    returned error exit status 2
2019-07-07 22:44:50,528 ERROR got an error from dpkg for pkg: 'sendmail-bin':
   'installed sendmail-bin package post-installation script subprocess
   returned error exit status 2'
2019-07-07 22:47:47,560 ERROR got an error from dpkg for pkg: 'sendmail':
    'dependency problems - leaving unconfigured'
2019-07-07 22:47:47,561 DEBUG running apport_pkgfailure() sendmail:
    dependency problems - leaving unconfigured
2019-07-07 22:47:47,561 DEBUG dpkg error because of dependency problems,
    not reporting against sendmail
2019-07-07 22:47:47,561 ERROR got an error from dpkg for pkg: 'sendmail':
    'dependency problems - leaving unconfigured'
2019-07-07 22:47:47,758 ERROR got an error from dpkg for pkg: 'sensible-mda':
    'dependency problems - leaving unconfigured'
2019-07-07 22:47:47,758 DEBUG running apport_pkgfailure() sensible-mda:
    dependency problems - leaving unconfigured
2019-07-07 22:47:47,759 DEBUG dpkg error because of dependency problems,
    not reporting against sensible-mda
2019-07-07 22:47:47,759 ERROR got an error from dpkg for pkg: 'sensible-mda':
    'dependency problems - leaving unconfigured'
2019-07-07 22:47:48,269 ERROR got an error from dpkg for pkg: 'inn2':
    'dependency problems - leaving unconfigured'
2019-07-07 22:47:48,270 DEBUG running apport_pkgfailure() inn2:
    dependency problems - leaving unconfigured
2019-07-07 22:47:48,270 DEBUG dpkg error because of dependency problems,
    not reporting against inn2
2019-07-07 22:47:48,270 ERROR got an error from dpkg for pkg: 'inn2':
    'dependency problems - leaving unconfigured'
2019-07-07 22:47:52,116 ERROR got an error from dpkg for pkg: 'dovecot-core':
    'triggers looping, abandoned'
2019-07-07 22:47:52,116 DEBUG running apport_pkgfailure() dovecot-core:
    triggers looping, abandoned
2019-07-07 22:47:52,132 ERROR got an error from dpkg for pkg: 'dovecot-core':
    'triggers looping, abandoned'
2019-07-07 22:51:47,341 ERROR Exception during pm.DoInstall()
Traceback (most recent call last):
  File "/tmp/ubuntu-release-upgrader-nggm0iiu/DistUpgrade/DistUpgradeView.py",
  line 220, in run res = pm.do_install(self.writefd)
apt_pkg.Error: E:Sub-process /usr/bin/dpkg returned an error code (1)
2019-07-07 22:51:47,369 ERROR SystemError from cache.commit():
    installArchives() failed
2019-07-07 22:51:47,370 ERROR found exception: ...

This bug was fixed in the package sendmail - 8.15.2-13

---------------
sendmail (8.15.2-13) unstable; urgency=medium

  * QA upload.
  * initscript: Let start-stop-daemon match on pidfile and executable.
    (Closes: #932598, LP: #1822866)

 -- Andreas Beckmann <email address hidden> Tue, 30 Jul 2019 19:22:43 +0200

I had to remove /var/run/sendmail/mta/sendmail.pid then it worked.