Cannot run `jj git push`: using ssh_key_from_agent loop

[prestonvanloon]

Description

Steps to Reproduce the Problem

1. jj git push

Not sure how I can provide a repro example. Just started using jj yesterday on an existing git repo.

Expected Behavior

It pushes

Actual Behavior

jj git push -v
2023-08-03T20:04:20.124904Z  INFO jj_cli::cli_util: verbose logging enabled
Branch changes to push to origin:
  Move branch assertion-api from eba925600601 to 2e9b7b55bbeb
2023-08-03T20:04:20.420168Z  INFO run_command: jj_lib::git: using ssh_key_from_agent username="git"
2023-08-03T20:04:20.443888Z  INFO run_command: jj_lib::git: using ssh_key_from_agent username="git"
2023-08-03T20:04:20.467704Z  INFO run_command: jj_lib::git: using ssh_key_from_agent username="git"
... 

The log statement INFO run_command: jj_lib::git: using ssh_key_from_agent username="git" is sent repeatedly in an apparent infinite loop.

Specifications

• Platform: linux amd64
• Version: jj 0.8.0-6ee8feea861c95f8246aee9e720ed5db66161006

[martinvonz]

Weird! I wonder if that's libssh2 doing retries for some reason (trying different keys? but you probably don't have that many different keys for it to try). Does ssh -F /dev/null git@<hostname> work and what does it output?

[prestonvanloon]

@martinvonz

ssh -F /dev/null git@github.com                      
PTY allocation request failed on channel 0
Hi prestonvanloon! You've successfully authenticated, but GitHub does not provide shell access.
Connection to github.com closed.

Not sure if this is related or not, but the repository was recently renamed and I still have the old remote url.
The command works for me on other repositories.

[martinvonz]

The ssh output looks as expected.

Not sure if this is related or not, but the repository was recently renamed and I still have the old remote url.
The command works for me on other repositories.

That's curious. Even if it's not related to the repo rename, it's a useful piece of data that it works in other repos. Does it work in a fresh clone of the repo?

[prestonvanloon]

Yes -- It works with a fresh clone of the repo. It also works if I clone it under the old remote url too.

[sullyj3]

same issue on jj 0.8.0-8c9fc9880c1796988f853d055b683f1ab70514b6. In an existing git repo.

[martinvonz]

Does it work in a fresh clone for you too, @sullyj3? I have no idea what might cause it.

[sullyj3]

Yeah, it did work. Bizarre.

[sullyj3]

Still works regardless of whether it was cloned with git clone followed by jj init --git-repo . or jj git clone.

[martinvonz]

Bizarre indeed. I don't know how to troubleshoot it more, so I'm going to rely on you and @prestonvanloon to try to figure out what's different between the old and the new repo. There is no retrying in jj's code anyway. I don't know how best to debug it even if i had access to your repos and environments. Maybe adding println!() statements in jj's code, or maybe libgit2 or libssh2 have some logging you can turn on. Or maybe even Wireshark.

[sullyj3]

If I run into it again I might become sufficiently curious to investigate further.

[jbcdnr]

Hello, I am hitting the same problem on a fresh repo #1979. There was no recent renaming of the repo I am trying to fetch or pull from.

[martinvonz]

I just looked up what libgit2 does and found https://libgit2.org/docs/guides/authentication/#:~:text=The%20callback%20drives%20the%20authentication,which%20authentication%20methods%20are%20available, which includes this:

If the server doesn’t accept the credentials from the callback, it will be called again. The callback drives the authentication loop. It will get called until it returns credentials accepted by the server or it returns an error code.

I suppose that's the loop you're running into. Can someone report what what ssh-add -l says?

[jbcdnr]

In my case:

$ ssh-add -l
The agent has no identities.

[martinvonz]

In my case:

$ ssh-add -l
The agent has no identities.

That would explain why jj can't get a key from it then. If you run ssh-add (and enter your password if it asks for it), does jj git clone work after that?

I don't know how git would find the key. Is your key password protected?

[jbcdnr]

Yes, it works now by adding explicitly the SSH key ! I don't know if git tries all of them or if I had configured which one to use at some point (but I don't think so).