Using the plug-in with some metadata fields, and looking for something like

LOCATION=

Will raise an exception in Jenkins log similar to this one:

line 0:-1 mismatched input '<EOF>' expecting NAME
com/sonyericsson/hudson/plugins/metadata/search/antlr/QueryWalker.g: node from line 0:0 no viable alternative at input 'LOCATION='

But in the user interface, all that the user gets is a "No jobs found" search result. It would be better if users received a feedback that their query is not valid.