No output using parallel in tandem with ag or ack

I have a list of java reserved words, first letter capitalised. $ tail -n5 ~/reservedjava.txt Break While True False Null I'm trying to look through all my java source code to find methods that look like getWhile(). cat ~/reservedjava.txt | parallel 'ag "get{}\(\)$"' This shows me nothing. Now, I know that I have a method getBreak(): $ ag "getBreak\(\)$" src/main/java/Foo.java 154: public Break getBreak() Here's what a dry run looks like: $ cat ~/reservedjava.txt | parallel --dry-run 'ag "get{}\(\)$"' | tail -n5 ag "getBreak\(\)$" ag "getWhile\(\)$" ag "getTrue\(\)$" ag "getFalse\(\)$" ag "getNull\(\)$" I'm using gnu parallel (v. 20130722) and the silver searcher (ag) (v. 0.18.1). If it makes a difference, I'm on Fedora 19, but have compiled these utilities myself. I get the same result with ack (v. 2.12).