Hey, I'm pretty sick, so no release tomorrow.
v589 should be out on the 11th. Thanks everyone!
>>/1689/
Ah I see, thanks. You might like to keep a page open, or save a favourite search, that has one 'system:url = http...' system predicate, and then when you want to do this search again, just open up that page and shift+double-click that predicate to edit it and paste your new URL in. Maybe that's quicker than regenerating it every time?
Another option, if you are ok doing a little bit of scripting, is asking via the Client API. You might be able to rig a .py script or something that you can paste an URL into to get a quick yes/no answer.
https://hydrusnetwork.github.io/hydrus/client_api.html
https://hydrusnetwork.github.io/hydrus/developer_api.html#add_urls_get_url_files
>>/1690/
If it doesn't, it should. I will check it out, thank you for the report!