The source package appears to be using a dh_ command but doesn't build depend on the package that actually provides it. If it uses it, it must build depend on it.
The tag is present in Lintian version
That is the most recent version we know about.
We use semantic versions.
The patch number is a commit step indicator relative to the
release tag in our Git
You can find the detection logic for this version at commit a1e47cb. For merge requests, please use the latest version in the Lintian check debhelper.