The standard environment variable for build options is DEB_BUILD_OPTIONS. Usually, referring to DEB_BUILD_OPTS is a mistake and DEB_BUILD_OPTIONS was intended instead.
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 131c0f4. For merge requests, please use the latest version in the Lintian check debian/rules.