shpool stops working due to client/server version mismatch

[wade-tregaskis]

AI Policy Ack
Ack.

What happened
I tried to reconnect to my shpool sessions and got this error message instead:

warning: client protocol ("0.4.1") is newer than daemon protocol (version "0.3.5"), try restarting your daemon
hit enter to continue anyway or ^C to exit

Contrary to what it says, hitting enter - or return, or any other key - made no difference, it always exited, refusing me access to SSH.

It's not clear to me what daemon is causing this, but it happens only when connecting to SSH aliases (in ~/.ssh/config) managed by shpool, not raw SSH. And restarting sshd didn't help, but restarting shpool did. But, restarting shpool killed all my open sessions, which defeats the point of using shpool to begin with.

What I expected to happen
If I hit return / enter it should let me connect.

Or better yet, it shouldn't have this problem to begin with.

To Reproduce
No idea - it just suddenly happened.

Version info
Server: shpool 0.10.1 (cl/921212711)
Client: ? (I'm just using ssh on macOS)

Logs
N/A?

[ethanpailes]

This is WAI. If shpool has a breaking protocol release the attach proc can no longer talk to the daemon proc. To talk to your existing daemon, you can downgrade your shpool to the 9.x version. You can also just restart your daemon if you are ok with dropping your existing sessions and re-creating them.

[wade-tregaskis]

I didn't upgrade anything to begin with (this is a corporate managed machine, I guess some management machinery did it), and that wasn't presented as an option in the error message.

Is it not still an error, at the very least, that it claims you can continue anyway, but you can't?

[wade-tregaskis]

I also think it should actually say what the problematic daemon is. Since the version numbers presented don't actually match shpool's version numbers.

[ethanpailes]

Connecting with an semver incompatible protocol version is best effort. Sometimes it will work, but sometimes (usually) it won't. There isn't a way to get around this unfortunately. I can re-open this and try to tweak the warning message to make that more clear.

Because of the library structure of shpool, it's a bit hard to surface the actual shpool version in the warning message, but I suppose I could update the way libshpool works to expose the shpool binary version to libshpool.

I think there may be a seperate issue with shpool 0.10.x, so I just yanked 0.10.0 and 0.10.1 until I can get to the bottom of it.

[mikelward]

I'm getting the reverse message. Unclear how restarting the daemon would help?

warning: client protocol (version "0.3.5") is older than daemon protocol (version "0.4.1"), try restarting your daemon

[ethanpailes]

This is probably because I yanked the last two versions of shpool because of a attach hang I haven't had the time to investigate (I may have been being overly paranoid about the issue). You probably picked up the new version, then got downgraded to the older version. Sorry for the disruption. Unfortunately your options are figuring out how to re-upgrade your currently installed version or just restarting your daemon and loosing your sessions.

If you work at google, you can DM me and I can help you out, if not, unfortunately there's not too much I can do to help in terms of OS level package stuff, but if your sessions are importaint enough you should be able to clone the repo and connect to your daemon using the current HEAD version.