Re: jessie to stretch upgrade Killed sudo.

["Martin McCormick" <martin.m@suddenlink.net>]

Jonas Smedegaard <jonas@jones.dk> writes:
> 
> I recommend to first make sure that the system tracks only packages from
> one single Debian release (not a mixture of multiple releases, and
> certainly not any non-Debian repositories).
> 
> (then I'd probably install etckeeper if not done already, to have a way
> of reverting some kinds of accidents in the following steps)
> 
> Then I'd check that all packages have fully upgraded and no packages are
> left that in not part of the new system.  Several ways to do that -
> personally I prefer using aptitude in fullscreen mode (i.e. start it
> with no non-option arguments) and look first at "Obsolete and Locally
> Created Packages" section, then "Upgradable Packages", and then _all_ of
> "Installed Packages" checking that the version is the one in the current
> system.
> 
> Then I'd inspect all packages recommended but not installed.  You
> certainly should know for sure that why each and every exception is
> there and that you really don't need it!  With aptitude that's done by
> hitting "CTRL+t" and in menu "Views" select "Audit Recommendations".
> 
> Then I'd purge all packages not installed.  In aptitude that's done by
> standing on the section "Not Installed Packages" and hit "_", and then
> "g" twice (skimming through what the list after first "g" to ensure
> nothing suspicious sticks out).
> 
> Then I'd inspect files below /etc - obvous bugs like broken symlinks,
> and unfinished merge of conffiles (look for *.dpkg* files).
> 
> 
>  - Jonas

Thank you.  I appreciate all the suggestions.  I have, so far,
solved the immediate problem.  It dates back to 2017.  A file
named /etc/pam.d/common-session which should be a 26-line
configuration file had been overwritten by nulls.  How that
happened, I do not remember but it is not a runtime-created file so I
replaced it with a copy of the same file from the working system
and sudo commands now work as they are supposed to.

	If there turns out to be any more issues, I will use the
steps you suggested plus compare file permissions and ownership of
all related files.  Fortunately, all the stretch systems I have
are basically copies of each other.

	Again, many thanks to all who responded.

Martin McCormick