I have observed serious usability issues prompting for credentials, when using a separate LFS server. In my case, I am using GitHub Enterprise, and a separate Artifactory server for LFS, though I don't believe those specifics would be necessary. The usability issues are severe enough for me to consider the case "unusable" and a bug.

Once credentials are cached, everything is smooth. However, if credentials have not been cached, prompting for them is basically usable. The workaround for the situation is to ensure credentials are cached (or stored) via an "out-of-band" mechanism. This isn't a good sell to potential Git LFS users, though. 😞

First, I appear to be prompted for the password once for each of the "ConcurrentTransfers" threads. These prompts are all strung together on a single line, and I have to enter credentials over and over again.

Additionally, after entering a username, the prompt for a password appears, but is immediately overwritten with an update on the status. Therefore, it's not clear that's there's even a prompt, much less what is required.

I've attached an image to attempt to demonstrate the usability issue in this situation. My configuration for the example is simply:

credential.helper=cache
http.sslverify=false
lfs.concurrenttransfers=8

It is the output of git lfs fetch from a repository cloned with GIT_LFS_SKIP_SMUDGE=1. The progress being made is as I attempt to enter my username and password multiple times, but I'm not even clear what I'm being prompted for, so I eventually give up. I don't want other users to go through the same thing!