scripts/fxtest/python/tests/test_data/build_output/package-targets.json

{
    "signed": {
        "targets": {
            "foo-test/0": {
                "custom": {
                    "merkle": "f00ba2deadbeef00000000000000000000000000000000000000000000000000"
                }
            }
        }
    }
}