Do a search, log in from the search results page, then you get something like

Oops, something went wrong!

Error:

Caught exception in MusicBrainz::Server::Controller::Search->search "Can't call method "process" on an undefined value at lib/MusicBrainz/Server/Controller/Search.pm line 38."
Stack trace:
line 38 MusicBrainz::Server::Controller::Search
line 330 MusicBrainz::Server
line 304 MusicBrainz::Server
line 331 MusicBrainz::Server
line 345 MusicBrainz::Server
line 390 MusicBrainz::Server
Request data:

$VAR1 = {
'query_parameters' =>

Unknown macro: { 'query' => 'foo', 'method' => 'indexed', 'type' => 'artist' }

,
'body_parameters' => {}
};

Host: pingu

URL: https://musicbrainz.org/search?query=foo&type=artist&method=indexed