We're having severe problems with the search backend so we've noticed that, even when failing completely and consequently returning 0 results, search fails silently.
It should tell the user that it failed and to try again in a dozen of seconds; and if possible also log it somewhere because debugging this is making one feel an haruspex.
Version: master
Severity: normal
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=6090