Comment 2 for bug 1724526

$ git clone https://github.com/schemaspy/schemaspy.git
Cloning into 'schemaspy'...
remote: Counting objects: 3570, done.
remote: Total 3570 (delta 0), reused 0 (delta 0), pack-reused 3570
Receiving objects: 100% (3570/3570), 29.24 MiB | 3.94 MiB/s, done.
Resolving deltas: 100% (1584/1584), done.
Checking connectivity... done.

$ cd schemaspy/
$ git tag
v6.0.0-beta.1
v6.0.0-beta.2
v6.0.0-beta.3
v6.0.0-rc1
v6.0.0-rc2

Try changing your `source-tag` to start with a "v".