selenium & chrome 78 failing basic authentication

Question

In a C# program, just installed chromedriver 78.0.3904.70: Loading URLs protected by Basic Authentication is now failing.

Before chromedriver 78: Setting driver.Url = [b

Answer 1

I logged a bug and got agreement that it's a bug, should be fixed in version 80. See https://bugs.chromium.org/p/chromedriver/issues/detail?id=3209 .

It does appear to have something to do with "committed interstitials" as @pcalkins proposes in the comments, but I couldn't find a way to verifiably set Chrome's http-auth-committed-interstitials flag in C#.