[zerolib] Why does this code always print 0.000000?

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LibC.cs

using System;
using System.Runtime.InteropServices;

unsafe class LibC {
	#if WINDOWS
		const string libc = "msvcrt";
	#else
		const string libc = "libc";
	#endif
	
	[DllImport(libc, CallingConvention = CallingConvention.Cdecl), SuppressGCTransition]
	public static extern int printf(byte* format, double x);
	
	public static int print(double x) {
		unsafe {
			var format = "%f\n"u8;
			fixed (byte* fmt = &format[0])
			{
				return printf(fmt, x);
			}
		}
	}
}

test.cs

using System;
using static LibC;

namespace ConsoleApp1
{
	class Program
	{
		static void Main(string[] args) {
			print(0.12345);
		}
	}
}

[ghost]

dotnet/runtime#98650