Confusing validation message

[vassilvk]

Consider the following:

schema.cue:

package my_package

// Top enum for all possible platforms.
#Platform: "linux/amd64" | "linux/arm64" | "windows/amd64" | "windows/arm64"

// Dynamic enum evaluated based on the actual set of platforms the container image was built for.
#ContainerImagePlatform : or(deployment_meta.container_image_platforms)

// Information injected by an external tool.
#DeploymentMeta: {
  // Container image platform - expected to be at least one of all the possible platforms.
  container_image_platforms: [#Platform, ...#Platform]
}

// User specified configuration.
#Workload: {
  deploy_platforms: [#ContainerImagePlatform, ...#ContainerImagePlatform]
}

// Concrete configuration sections.
deployment_meta: #DeploymentMeta
workload: #Workload

values.yaml:

# Generated by external tooling.
deployment_meta:
  container_image_platforms:
    - linux/amd64
    - linux/arm64

# Provided by user.
workload:
  deploy_platforms:
    - windows/amd64

Here's the goal:

• deployment_meta.container_image_platforms should be one of ["linux/arm64", "linux/amd64", "windows/amd64", "windows/arm64"].
• workload.deployment_platforms should match one of the values in deployment_meta.container_image_platforms.

The above YAML file contains an intentional validation issue to demonstrate the problem.
List workload.deployment_platforms contains windows/amd64 which is not on the list of items in deployment_meta.container_image_platforms.

Running vet values.yaml schema.cue generates the following:

workload.deploy_platforms.0: 3 errors in empty disjunction:
workload.deploy_platforms.0: conflicting values "linux/amd64" and "windows/amd64":
    ./schema.cue:17:22
    ./schema.cue:22:11
    ./values.yaml:4:7
workload.deploy_platforms.0: conflicting values "linux/arm64" and "windows/amd64":
    ./schema.cue:4:28
    ./schema.cue:12:31
    ./schema.cue:17:22
    ./schema.cue:22:11
workload.deploy_platforms.0: conflicting values "windows/arm64" and "windows/amd64":
    ./schema.cue:4:62
    ./schema.cue:12:31
    ./schema.cue:17:22
    ./schema.cue:22:11

I'm not sure I understand where the third message (about windows/arm64) is coming from, as windows/arm64 is not in the deployment_meta.container_image_platforms list.

[jpluscplusm]

Hey @vassilvk 👋

So I was confused by this as well, and I went digging :-) I've raised #2912 to flag the behaviour as a bug.

I've phrased the issue in terms of the (seemingly) superfluous and confusing conflicting value flagged by the disjunction, so hopefully the new evaluator that's being developed can prefer the form of the error message that would be useful here.

However, given that it's also an ordering-related issue, I'm not sure what fix might ultimately be proposed, and if it would make the output less confusing. I hope it will, of course!

I'm not sure if you can affect the ordering sufficiently, in your more complete example, to avoid the confusing, conflicting value. I wasn't able to make that work, here, but maybe you'll have better luck since you control the wider shape of your CUE and your data.