sfdx force:source:pull -> Entity of type 'AuthProvider' named '' cannot be found
Make sure your AuthProvider name has no spaces.
I was able to pull the metadata using the retrieve command:
sfdx force:source:retrieve -m AuthProvider
However, your subsequent pull commands will continue to fail because it cannot find the AuthProvider.
If you rename it replacing spaces with underscores (Name and URL Suffix will both have no special chars) pull commands will work just fine.
Hope this helps.
Jose
I was able to selectively pull the problematic metadata using this plugin https://www.npmjs.com/package/@rohanatgwcs/sfdx-selective-retrieve-deploy
sfdx gs:source:pull --type AuthProvider --names MyProvider --targetdir force-app/main/default/authProvider