Intermittent issue with installing versions

I'm experiencing something similar to #406 but without a company-managed Apple ID. Importantly, this is only happening intermittently, but it happens enough to be a blocker in many cases.

There are two commands that are failing intermittently:

1. xcodes update --data-source apple
2. xcodes install <version>

In both cases, I see the following error in the terminal:

The operation couldn’t be completed. (DecodingError.dataCorrupted(Swift.DecodingError.Context(codingPath: [], debugDescription: "The given data was not valid JSON.", underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840 "Unexpected character '<' around line 1, column 1." UserInfo={NSDebugDescription=Unexpected character '<' around line 1, column 1., NSJSONSerializationErrorIndex=0}))))

From the error it seems like the endpoint that is being requested is returning HTML instead of JSON. Is there a way we can debug this by printing out the response from Apple's servers? Failing that, what curl command can I use to make a similar request, to see what Apple is returning?

Just to note that I'm also seeing the same issue in the Xcodes app.

Things I've tried:

• Using xcodes signout and re-authenticating
• Changing the password in my Apple account

Screenshots

Start with the xcodes update --data-source apple and xcodes install <version> entry points and reproduce the intermittent DecodingError.dataCorrupted response. Inspect the response from Apple's servers, including cases where HTML is returned instead of JSON. Done means the failure is diagnosed and the relevant error handling or debugging output is improved for both CLI commands.