Repo - bad work.
I made a change in hrev50745 to drop a previously required field in the repo definitions. A breakage was assumed unless you upgraded to hrev50723 - hrev50744 before upgrading beyond.
The 3rd party repos breaking is an odd side effect. They must regenerate those repos from a freshly compiled repo tool from our sources.
I’m going to re-stub out the url field, should solve the issue for now and other devs say they’re fine with a bit of trash hanging around for compatibility.
Compatibility field re-added to hrev50748. Give those repos some time to catch up and you should be back to working. (~24 hours?)
hrev50753 - boot failed 
Boot failure should be fixed in hrev50754.