Comment 4 for bug 2063124

> I believe that Subiquity-side, on shutdown of the server process, the outstanding waiting API calls are returning null. This is outside the API contract of /meta/status, which claims to only return ApplicationStatus.

This is not exactly what I observed. On shutdown, it seems that the server simply closes the connection without replying to the query:

+ curl --unix-socket .subiquity/socket 'http://a/meta/status?cur="WAITING"' -v
* Trying .subiquity/socket:0...
* Connected to a (.subiquity/socket) port 80
> GET /meta/status?cur="WAITING" HTTP/1.1
> Host: a
> User-Agent: curl/8.5.0
> Accept: */*
>
* Empty reply from server
* Closing connection
curl: (52) Empty reply from server