Show GitHub issues that do NOT contain a label

Question

About once a week a newcomer finds my GitHub project, asks "Is there an issue that nobody works on and that I could fix?", fixes it, then disappears forever. Yesterday two newcomers fixed the same issue independently, which resulted in wasted time and frustration. I want to prevent that from happening again. I have set up a Wiki page explaining how to see the issues that are currently NOT assigned:

Go to https://github.com/commons-app/apps-android-commons/issues?utf8=%E2%9C%93&q=is%3Aopen%20is%3Aissue%20no%3Aassignee and choose an issue that does NOT have the "assigned" label.

How to make this instruction shorter by including in the URL the fact that issues with the "assigned" label should be ignored?

Note: Apparently I can only assign issues to people who belong to my organization. That's why I had to create the "assigned" tag.

Answer 1

You can use the -label qualifier for that. Adding -label:assigned will remove any issues with the assigned label from the filtered results. The URL with that filter included would be:

https://github.com/commons-app/apps-android-commons/issues?utf8=%E2%9C%93&q=is%3Aopen%20is%3Aissue%20no%3Aassignee%20-label%3Aassigned

That URL will load your Issues page filtered by the following rules:

is:open is:issue no:assignee -label:assigned 

You can read more details about the syntax on this GitHub help page.