Weird bug a colleague has encountered:
A server implemented in C# receives JSON data and decodes it with System.Text.Json. The JSON data contains an array with null elements.
The server is running in a Docker container.
The server, when run on Windows, handles the JSON fine.
On a Ubuntu server it doesn't, because for some reason the decoded array contains null literals rather than a JsonElement of kind Null. That's a problem when a function expects a JsonElement, so C# throws an ArgumentNullException.
How the fuck does this happen?