Update: this is due to the validator not applying the schema ID correctly, it only handles an object, not an assoc array.

I have this schema:

{
    "id": "tests/schemas/suggest/empty.schema.json",
    "allOf": [
        {
            "$ref": "baseline.schema.json"
        }
    ],
    "properties": {
        "items": {
            "maxItems": 0
        }
    }
}

With the update to 6.x, this fails with

      file_get_contents(internal://provided-schema/tests/schemas/suggest/baseline.schema.json): Failed to open stream: No such file or directory (JsonSchema\Exception\ResourceNotFoundException)

I guess the schemaless ref is now interpreted as internal in some way?

If I modify my schema as so

{
    "id": "tests/schemas/suggest/empty.schema.json",
    "allOf": [
        {
            "$ref": "file://tests/schemas/suggest/baseline.schema.json"
        }
    ],
    "properties": {
        "items": {
            "maxItems": 0
        }
    }
}

Now it says

      file_get_contents(file://tests/schemas/suggest/baseline.schema.json): Failed to open stream: no suitable wrapper could be found (JsonSchema\Exception\ResourceNotFoundException)

which means it understands it needs to read the file locally. For some reason, it doesn't read the file even though it exists.

If I add

$uri = substr($uri, 7);

to strip file:// before here, it works.

Should this happen conditionally, if there's a file:// prefix, strip it? There's some file:// special handling a little later in the function, but it's already too late because an error was raised.