[gthumb-list] catalog: volume doesn't implement mount

[jyqvklioo googlemail com]

Greetings,
I am running GThumb from git head.
Is that a bad idea?
Should I instead run the most recent tag?
        I get an error message:
Could not load the position "catalog:///Example.catalog"
volume doesn't implement mount
        Is that indicative of something misconfigured when I build or a fault or incomplete source code?
I do not notice any problem reported by configure.
Should I recieve a reply: thank you in advance.