Per-request AddCredential not working with BatchRequest

With the per-request credential example provided by @amanda-tarafa in #2064, I was able to get it working for services like Calendar and Oauth2. But I’m having trouble with GmailService.

I use GmailService via BatchRequest, like this

var cred = GoogleCredential.FromAccessToken(myToken);

var batchRequest = new BatchRequest(_gmailService);

foreach (var gmailMessage in gmailMessages)
{
    batchRequest.Queue<SendRequest>
        (_gmailService.Users.Messages.Send(gmailMessage, "me").AddCredential(cred), myCallback));
}

await batchRequest.ExecuteAsync();

I’m getting error:

Error 401, Request is missing required authentication credential. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.

[amanda-tarafa]

@mikequ-taggysoft Yes, this is still on my radar, but as @jskeet said some higher priority work popped up. We’ll work on this for sure.

[jskeet]

@mikequ-taggysoft: Amanda is currently on vacation, and when she’s back there are higher priorities. We haven’t forgotten about this and will get to it, but I’m afraid we do need to prioritize work that will affect more customers.