Conflicting values when removing upper levels in a struct

[fresus]

Hi there!

I'm using cue to generate a docker compose file for multiple "stacks" but I'm having issues when I try to transform them to compose services.

This works as expected:

stacks: {
        a: {
                services: a1: networks: ["a", "b"]
                services: a2: networks: ["a"]
        }
        b: services: b1: networks: ["b"]
}

services: {
        for stack in stacks {
                stack.services
        }
}

But if I want all services in a stack to share a network by default by adding something like this:

stacks: [ID=_]: services: [string]: networks: [
        ID,
        ...,
]

It breaks with these errors:

services.a1.networks.0: conflicting values "b" and "a":
    ./test.cue:5:28
    ./test.cue:11:37
    ./test.cue:12:2
    ./test.cue:26:2
    ./test.cue:27:3
services.a2.networks.0: conflicting values "b" and "a":
    ./test.cue:6:28
    ./test.cue:11:37
    ./test.cue:12:2
    ./test.cue:26:2
    ./test.cue:27:3
services.b1.networks.0: conflicting values "a" and "b":
    ./test.cue:8:30
    ./test.cue:11:37
    ./test.cue:12:2
    ./test.cue:26:2
    ./test.cue:27:3

And it works again if I remove these lines:

services: {
        for stack in stacks {
                stack.services
        }
}

I recently found a workaround but I don't see the differences with the previous solution:

services: {
        for stack in stacks
        for k, v in stack.services {
                "\(k)": v
        }
}

What am I missing? Thanks in advance.