Use dpkg packet assembly on a project..
dch -v 1.2.3
The changelog file changed as expected:
package (1.2.3) UNRELEASED; urgency=medium
*
-- Maintainer <email@example.com> Fri, 08 Nov 2019 20:11:21 +0300
Then I use:
dch --release
The changelog reports the following:
package (1.2.3) bionic; urgency=medium
...
instead of the expected:
package (1.2.3) unstable; urgency=medium
...
as described in man dch.
Please advise..
P.S. using Mint OS.
The upstream Debian package devscripts behaves exactly as per the documentation. The problem is that you are using an Ubuntu-derived OS which has made some changes without updating the documentation.
This is a known bug: https://bugs.launchpad.net/ubuntu/+source/devscripts/+bug/1655717
Maybe you should raise a separate Mint bug because it doesn't look like Ubuntu is going to change this any time soon. Or switch to a platform which is not based on Ubuntu if Mint is not central to your usage scenario.
The dch documentation shows how to work around this.
dch --release --distribution unstable