This Travis run shows an unexpected ArgumentError in Proc#call after sequential calls to #curry and #call

Effective code is:

l = lambda{|a,b,c| a+b+c }
l1 = l.curry.call(1)
l2 = l1.curry.call(2)
l2.curry.call(3) #=> 6
l1.curry.call(2,3) #=> ArgumentError

Ruby version is: jruby 1.7.9 (1.9.3p392) 2014-02-10 87b108a on Java HotSpot(TM) 64-Bit Server VM 1.7.0_51-b13 [linux-amd64]