This looks like a bug in DAVix.
The getVersion operation is described as:
This method can be used to query the version of the service.
For dCache, we return the dCache version. So, prometheus returns "4.2.0-SNAPSHOT" (the "SNAPSHOT" is because haven't actually released dCache v4.2.0 yet).
It looks like this code may have worked-by-accident with earlier dCache versions.
My guess would be that the code should be calling getInterfaceVersion instead. This is described as:
This method can be used to query the version of
the supported interface.
For this, we return a hard-coded "2.0.0" string, which should work as expected.
to check if the getInterfaceVersion will work also with other Implementation ( ie. DPM)