windows: error cannot lock ref ... unable to create lock

I've set up a demo problematic repository on github: https://github.com/asottile-archive/git-windows-branch-test

The minimal reproduction is:

rm -rf x git init x cd x git remote add origin https://github.com/asottile-archive/git-windows-branch-te> git fetch origin --tags

Here's the output:

+ git init x
Initialized empty Git repository in C:/Users/IEUser/x/x/.git/
+ cd x
+ git remote add origin
https://github.com/asottile-archive/git-windows-branch-test
+ git fetch origin --tags
remote: Enumerating objects: 10, done.
remote: Counting objects: 100% (10/10), done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 10 (delta 0), reused 0 (delta 0), pack-reused 0
Unpacking objects: 100% (10/10), done.
From https://github.com/asottile-archive/git-windows-branch-test
 * [new branch]      master     -> origin/master
error: cannot lock ref 'refs/remotes/origin/pr/aux': Unable to create
'C:/Users/IEUser/x/x/.git/refs/remotes/origin/pr/aux.lock': No such
file or directory
 ! [new branch]      pr/aux     -> origin/pr/aux  (unable to update local ref)

real-world issue: https://github.com/pre-commit/pre-commit/issues/1058

Thanks

Anthony