pkg/front_end/test/language_versioning/data/package_non_package_default_version/.dart_tool/package_config.json

{
    "configVersion": 2,
    "packages": [
        {
            "name": "foo",
            "rootUri": "../",
            "packageUri": "lib/",
            "languageVersion": "2.5"
        }
    ]
}