Last modified: 2014-04-16 19:17:15 UTC
https://en.wikipedia.org/w/index.php?title=Special%3ASearch&profile=all&search=Comparison+of+Windows+7+editions&fulltext=Search fails with: | An error has occurred while searching: The search backend returned an error: but no further message. This also fails for "Comparison of Windows 7". "Comparison of Windows" or shorter, "7", four other words, etc. work.
Works with &srbackend=CirrusSearch : https://en.wikipedia.org/w/index.php?title=Special%3ASearch&profile=all&search=Comparison+of+Windows+7+editions&fulltext=Search&srbackend=CirrusSearch
Going to Special:Search and typing in "Comparison of Windows 7 editions" works as well (https://en.wikipedia.org/w/index.php?title=Special%3ASearch&profile=default&search=Comparison+of+Windows+7+editions&fulltext=Search). The difference compared with the failing URL above is "profile=all" vs. "profile=default". BTW, forgot to mention that the original bug was reported today by jackmcbarn in #wikimedia-operations.
This is a bug in lsearchd, moving and WONTFIXing as appropriate. Cirrus doesn't have this problem.