Upterm action failing with "command not found"

[pcd1193182]

Hey, I'm trying to use the upterm action to debug some test failures, and it appears to be failing. This used to work (as of a month ago or so). I'm not hosting my own upterm server or anything, but the runs are failing like this:

=== YU0HKZGLXX4IWRUUUFRM                                                                                         
Command:                tmux new -s upterm -x 132 -y 43                                                         
Force Command:          tmux attach -t upterm                                                                   
Host:                   ssh://uptermd.upterm.dev:22                                                             
SSH Session:            ssh Yu0hKZGLXx4IWRuuufRM:[email protected]

bash: upterm: command not found

127

Given the lack of configuration options, I'm reasonably sure this isn't something I messed up somehow, unless this type of runner is no longer supported.