Using `git lfs` with SSH on GitHub gets stuck at `git-lfs-transfer`

Question

I noticed that git lfs operations (push or pull but especially push) with GitHub keep getting stuck running git-lfs-transfer. This is slowing down all of my git operations which call git lfs via hooks.

Here's an example (I just found a public repo with an lfs file):

git clone [email protected]:cbeams/lfs-test.git
cd lfs-test
GIT_TRACE=1 GIT_TRACE_CURL=1 git lfs pull

this often hangs at this step:

15:20:53.004384 trace git-lfs: exec: ssh '-oControlMaster=yes' '-oControlPath=/run/user/1000/sock-881286357/lfs.sock' '[email protected]' 'git-lfs-transfer cbeams/lfs-test.git download'

Sometimes it succeeds quickly, sometimes after a very long time. If I Ctrl+C and cancel the command out of impatience, then all authentication to GitHub fails for a while:

$ ssh -v [email protected]
OpenSSH_8.9p1 Ubuntu-3ubuntu0.13, OpenSSL 3.0.2 15 Mar 2022
...
debug1: Connecting to github.com [140.82.114.3] port 22.

Additionally, running the git-lfs-transfer shown in the above stuck line results in:

$ ssh [email protected] 'git-lfs-transfer Apress/repo-with-large-file-storage.git download' 
Invalid command: git-lfs-transfer Apress/repo-with-large-file-storage.git download
 You appear to be using ssh to clone a git:// URL.
 Make sure your core.gitProxy config option and the
 GIT_PROXY_COMMAND environment variable are NOT set.

git lfs pull seems to pull the file anyway despite that error which is confusing.

Here are my versions:

$ git-lfs --version
git-lfs/3.7.1 (GitHub; linux amd64; go 1.24.4)
$ git --version 
git version 2.34.1

• phd: "If I Ctrl+C and cancel the command out of impatience, then all authentication to GitHub fails for a while" I suspect it's because ssh started by git lfs with option ControlMaster=yes is still running; authentication fails until running ssh timed out. To stop it try ssh -O exit [email protected] .
• hlovdal: 2.34.1 is 4 years old, the latest version is 2.52.0. I would be really surprised if there has not been updates to the lfs functionality in those 4 years.
• sciencectn: @phd ssh needs ControlPath when doing -O exit. But as far as I can tell, the connection doesn't start. The control socket path in /run/user/1000/sock-... doesn't get created.