cue eval topschema.cue foo.textproto
cmp stdout out/topfoo.textproto

cue eval -d '#X' schema.cue foo.textproto
cmp stdout out/foo.textproto

! cue eval -d '#X' schema.cue foo.textproto -l c
cmp stderr out/stderr3

-- topschema.cue --
a: int
b: [...int]
c: string
-- schema.cue --
#X: {
        a: int
        b: [...int]
        c: string
}
-- foo.textproto --
a: 4
b: 1
b: 2
b: 3
b: 4
b: 5
c: "foo"
-- out/topfoo.textproto --
a: 4
b: [1, 2, 3, 4, 5]
c: "foo"
-- out/foo.textproto --
a: 4
b: [1, 2, 3, 4, 5]
c: "foo"
-- out/stderr3 --
cannot combine --schema flag with flag "path", "list", or "files"