call terra functions from lua no longer automatically unpacks multiple return values.
instead you can call terralib.unpackstruct in lua:

terra foo() return 1,2 end
local a = foo() --a cdata struct of 1,2
local b,c = terralib.unpackstruct(foo()) --1, 2
make sizeof/terralib.sizeof and unpackstruct/terralib.unpackstruct
the same object. Each has different behavior when run as a macro vs. directly from Lua code.