cue eval -c -a
cmp stdout eval_conc.cue

cue eval --out yaml
cmp stdout eval_conc.yaml

-- eval_conc.cue --
message: "Hello World!"
-- eval_conc.yaml --
message: Hello World!
-- cmd_echo.out --
Hello World!

-- data.cue --
package hello

#who: "World"
-- hello.cue --
package hello

message: "Hello \(#who)!" // who declared in data.cue
