This is the first time I have seen this with any package.

I have no idea whether it has happened with packages not installed on my
systems.

It is my understanding that best practice is noexec on /tmp and that
this is a Debian recommendation.

Here is the relevant line from /etc/fstab.

tmpfs   /tmp    tmpfs defaults,noatime,mode=1777,nosuid,noexec,nodev  0  0


Here is the error message.

sudo apt-get dist-upgrade

.

.

Preconfiguring packages ...
Can't exec "/tmp/openvpn.config.NDxHMl": Permission denied at
/usr/lib/x86_64-linux-gnu/perl-base/IPC/Open3.pm line 178.
open2: exec of /tmp/openvpn.config.NDxHMl configure 2.5.1-3+devuan1
failed: Permission denied at /usr/share/perl5/Debconf/ConfModule.pm line 59.
.

.

The (apparent) recommendation from bug report 129289 in 2002 is to set

APT::ExtractTemplates::TempDir
in apt.conf to some directory which is mounted with exec

and
As of version 0.5.8, apt supports TMPDIR for determining where
apt-extracttemplates puts its temporary files. If you have a noexec
/tmp, use this or other documented means to make apt-extracttemplates
use a directory that does accept executables

As of 2018 Bug #887099, merged with sundry other bug reports of the same type
Control: reassign -1 debconf 1.5.61
Control: forcemerge 566247 -1

This appears to be a generic issue in debconf, so I'm reassigning it to
debconf and merging it with the existing bugs tracking the same issue.

There doesn't seem to be any activity after that.

Is there a best practice for the method of selecting and setting this
directory?

Thanks,

Ken