The DEP 12 metadata file in the source is not readable. This could be caused by a dangling symlink, or that the name is used by some non-file directory entry.
For more information please consult:
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 ea05801. For merge requests, please use the latest version in the Lintian check debian/upstream/metadata.