Cross-platform key sorting issue

[finestructure]

We've just run into a fun problem where a JSON snapshot has different key sorting (with sortedKeys output formatting set) between platforms. The reason is that Linux and macOS have different ideas how to sort capital letters. Specifically, macOS renders this snapshot:

          "signer" : {
            "commonName" : "Swift Package Index",
            "organizationalUnitName" : "Swift Package Index",
            "organizationName" : "Swift Package Index",
            "type" : "ADP"
          },

whereas Linux has this:

          "signer" : {
            "commonName" : "Swift Package Index",
            "organizationName" : "Swift Package Index",
            "organizationalUnitName" : "Swift Package Index",
            "type" : "ADP"
          },

I know this isn't really a swift-snapshot-testing problem but I was wondering if anyone has any ideas how to deal with this.

Things I'm considering:

• record two different snapshots, per platform (not ideal, because we develop on macOS and CI runs on Linux and it'll drift)
• try and override how this particular struct is being encoded somehow (not sure if it's possible to re-conform to Codable and make it stick - I wouldn't mind a hack, it's inside tests only)

[finestructure]

Great news: the swift 6 nightly toolchains now sort the same on Linux as on macOS and the work-around with platform specific snapshots isn't needed anymore.