You didnt do it right..
alias test { query codemastr | var %var = codemastr | return %var }
is wrong. It should be:
alias test { query codemastr | set %var codemastr | return %var }
you wrote "var %var = codemastr"
it should be: set %var codemastr
So when I do the right one, I get: * /echo: insufficient parameters
So, problem reprodused