JSONDecoder.convertFromSnakeCase在iOS 13中停止工作了吗？

Question

升级到Xcode 11 / iOS 13之后，先前有效的单元测试失败，因为JSONDecoder抱怨期望的密钥丢失。

我要解析的JSON：

{
  "documentation_url": "http://www.discogs.com/developers/",
  "statistics": {
    "labels": 1420380,
    "releases": 11630155,
    "artists": 6465084
  },
  "hello": "Welcome to the Discogs API.",
  "api_version": "v2"
}

我要解码的类型：

public struct DiscogsInfo: Codable {
    public var apiVersion: String?
    public var documentationUrl: URL
    public var hello: String
    public var statistics: Stats

    public struct Stats: Codable {
        public var labels: Int
        public var artists: Int
        public var releases: Int
    } 
}

错误：

(lldb) po error
▿ JSONErr
  ▿ parseFailed : 1 element
    ▿ error : DecodingError
      ▿ keyNotFound : 2 elements
        - .0 : CodingKeys(stringValue: "documentationUrl", intValue: nil)
        ▿ .1 : Context
          - codingPath : 0 elements
          - debugDescription : "No value associated with key CodingKeys(stringValue: \"documentationUrl\", intValue: nil) (\"documentationUrl\")."
          - underlyingError : nil

还有解码器：

(lldb) po jsonDecoder.keyDecodingStrategy
Foundation.JSONDecoder.KeyDecodingStrategy.convertFromSnakeCase

我唯一能想到的就是iOS 13以某种方式忽略了keyDecodingStrategy。