"alda list" output is buggy when multiple servers are running

[daveyarwood]

$ alda list
[49816] Worker (pid: 27897)
[49816] Worker (pid: 28585)
[27713] Server up (2/2 workers available, backend port: 49816)
[27714] Server up (2/2 workers available, backend port: 49816)

$ alda -p 27713 status
[27713] Server up (2/2 workers available, backend port: 49816)

$ alda -p 27714 status
[27714] Server up (0/0 workers available, backend port: 60444)

(Note: disregard the "0/0 workers" part; it makes sense here, as I happened to be running a server with the --workers 0 option.)

For some reason, when listing Alda processes with alda list, I'm seeing the status line for one server repeated verbatim for the other server, with only the port differing. When running alda status individually for each port, it is clear that they should be different. There is probably some race condition in the client code that lists the processes.