Hi all, after upgrading to MessagePack 3.1.4, some of my serialization code now fails. One issue seems to be caused by the change in MessagePackWriter.Write(ulong value).

In version 2, the size of the required span depends on the value being serialized. In version 3, it is 9 by default:
AssumesTrue(MessagePackPrimitives.TryWrite(writer.GetSpan(9), value, out var bytesWritten));

When serializing to a fixed sized buffer ( for example, when manually serializing a gRPC payload where the size is precalculated), the buffer might be smaller than the required span. And the buffer cannot be (and shouldn't be for performance reason) resized.
When serializing a ulong value of 0, the write will fail when trying to allocate 9 bytes, even though it only requires 1 byte to serialize the value.