When running minicom as a user in the dialout group I now get an error message
that it cannot create a lock file.  This worked in 15.5.  Minicom is attempting
to create the lockfile in /run/lock but only root has write access to this
directory.  Minicom uses lockdev which requires access to /var/lock.

One way to fix this is to build minicom without lockdev.  Lockdev is
fundamentally broken because it requires write access to /run/lock, which is a
security nightmare.  When minicom is built without lockdev the location of the
lockfiles can be specified to be someplace other than /var/lock.

See
https://systemd-devel.freedesktop.narkive.com/vCJLfMo2/headsup-var-lock-and-var-lock-lockdev
for a discussion.

As an interim solution, I added an ACL to allow the dialout group to write to
/run/lock, though this is far from ideal.