This is missing the type, the line should be

    DiffFlagBinary DiffFlag = C.GIT_DIFF_FLAG_BINARY

and analogously to the rest (you can skip the type in the rest, but the first one in the block must have it). Otherwise, the type is going to be an int, which would not give us the type safety (and it would fail if we had some test code that exercised a function that wants a `DiffFlag`).