Git-credential-manager-for-windows: Uninstalling GCM and Git for Windows, then reinstalling GCM with the Git for Windows installer wiped WIndows Credential manager entries on restart

[portaljacker]

Recently GCM kept prompting me for my Github credentials after each restart of my PC, this started about Sunday or so. This also coincided with the OneDrive application asking me for my password every restart as well (as it seems it uses Windows Credential Manager as well).

My last attempt to solve the issue I logged into git through GCM (it showed the github style login window, then the 2FA window with the 6 boxes) which logged it in Windows Credential Manager. Then I uninstalled Git for Windows (which also removed GCM), restarted, and the entry was still there. I then i re-installed Git for Windows with the GCM option enabled, and restarted. Then poof, all my Windows Credential Manager options vanished (including Microsoft Account and Xbox Live entries).

Edit: forgot to mention this is Windows 10 Home 64-bit.

[whoisj]

The Git Credential Manager for Windows does use the Windows Credential Manager as a secure storage vault to secrets. Uninstalling the GCM does not remove secrets from the vault (this is intentional behavior and not likely to change), so no surprise there. As for the sudden disappearance of all credentials: this is the first I've heard of that. The GCM should not delete credentials which are not prefixed with "git:" and/or "ada:".

Thanks for the report.

[portaljacker]

No problem, if you need any more info I'll be able to provide it in about 7 or so hours once I'm home from work if it needs my PC to get it.

The only other coinciding event is installing the Visual Studio 2017 RC and uninstalling 2015. I doubt it's related, but it was done the same day.

I checked my chat history with a friend I talk to about dev stuff, and my first mention of the issue is Monday evening, but since a restart is required to trigger it seems, the aggravating event is likely on Sunday.

[portaljacker]

So this is extremely irritating...but it works now. I literally haven't used my computer in the time since I logged this ticket... I turned it on, git push to add credentials, it saves, restart...and it's still there! Restart again, still there.

I legitimately have no idea what happened...

[portaljacker]

Wait, spoke too soon, just opened it and it was gone. Meaning something on login is doing it!

[portaljacker]

I can reliably produce the result now, sometime after login, after it seems all my startup applications open Windows Credential Manager clears all entries. (checked by constantly clicking refresh in that window)

[whoisj]

The GCM most likely shouldn't be running at logon.

You can add GCM_TRACE to your environment to force the GCM to trace any activity to a file. Just make sure the value of the key is a path to a file. Note that the GCM will not create directories for logging, but it will create/append a file.

[portaljacker]

So I'll start for apologizing for wasting your time, and let you know it's because I'm an idiot.

TL;DR I messed with the SYSTEM user and it messed with me.

Full explanation:

About a month ago I had an issue with git not finding my global gitconfig in my user folder. I found my HOME directory was in C:\Windows\System32\config\systemprofile! So I read some advice wrong about fixing the issue and changed the value of user S-1-5-18's profile to mine.

Fast forward to Sunday, I'd been having random issues, but nothing seemed connected, Netflix was crashing on launch, then after installing VS 2017 RC on Sunday, my issues began with git, leading to this ticket.

So the fix for this issue was to change the directory for S-1-5-18 back to C:\Windows\System32\config\systemprofile, then realized why my HOME was pointing there, home is set to USERPROFILE as a system variable, for system it's systemprofile, and then looked up...I had no USERPROFILE set.

Why that happened, I'm still not sure, but GCM works again, Netflix works again. I only just realized my gmail wasn't syncing in the Win10 mail app and it works too.

I guess now all I can do is figure out what erased my USERPROFILE variable. I can narrow it down to 2 apps I installed the day the original issue started, MiKTeX & Strawberry Perl, but I of course will do this on my own, since this isn't a general help forum.

Thanks for your time!

[whoisj]

@portaljacker thank you very much for following up and with a helpful, for the next person to read and learn from, explanation. This is very much in the spirit of open-source and exactly the kind of resolution that we're looking for.

🙇

[portaljacker]

It helps that I'm used to writing formal tickets and responses at work, and with these issues in particular I found lots of non-answers or very unsatisfying answers (eg. make a new user! As if that wasn't a huge burden on a personal PC...), so I knew I had to let people know my solution.

Plus this project is in C#, so I think I'll poke around the issues and see if I can help out. I'm still a junior dev, but I'm sure there's stuff I could help with.