Prerelease app is broken because of a Rack/Unicorn incompatibility

[nickcharlton]

We're getting the following error log when trying to load /admin on the prerelease demo app:

2024-12-24T14:40:15.544423+00:00 app[web.1]: E, [2024-12-24T14:40:15.544391 #5] ERROR -- : app error: undefined method `=~' for ["_administrate-prototype_session=aW1pVHNZcmF0WG9zSHJ0UEFJQWI5cUxKRjVWS2JuUWZxZktMSENRclhEQTZlZzY2VVQzTEc3d1VVR21wU3RaRGU4cWtWazVOM29UdCt4VzFMU0lPMG5MZ1hXakc3RHpWV1ExcEdwZHdBWUdyQXozT2ZMQ3Y2RU1PVUhwcGZLWG9DT1pid05tSUJhdGJoSVpyVlovNUljYkpWMzRBK1hhUFdzQTdMRFNnb05vUTMvaTRXQzlCOUFQaE4wYjdCblNWLS02YldIejUrMzZnS3RwcWZBcDJrMEFnPT0%3D--3e7eabdc3aa263fc3c2c45256b73a7638b067b4e; path=/; secure; httponly"]:Array (NoMethodError)

It sounds like it's an incompatibility with Rack 3 and Unicorn, the last release of which was 6.1.0 on 2021-12-25.

Options:

1. Switch to Puma
2. Monkey-patch Rack 3 support in whilst we wait for a new Unicorn release