Terry Roy <tech@futurecourse.com> writes:
I found a bug in Debian's latest 9.3 update where the postinst script
of a package contained the line:
"su - username do something...."
I've just run this command:
grep "su - " /var/lib/dpkg/info/*
which returned no results on a system with thousands of packages
installed. So I tentatively conclude that it's not a common pattern.
I've just run across it again on a fresh install of another package.
I've reported that bug but clearly this seems to be an issue involving
the use of "su -" in postinst.
You should proceed this way, IMO. Report a bug against each package that
uses that invocation.
I note that a similar pattern, invoking ‘su’ to run commands as another
user, is in the ‘postgresql-common’ package:
su -s /bin/sh postgres -c "… more commands …"
If you alter the postinst script to use that pattern instead, does it
avoid the problem you describe? If so, you can suggest that to the
package maintainer.