File.Move throws IOException on macOS when rename differs only by case

[bording]

If File.Move is used on macOS to rename a file that differs only by case, it fails:

class Program
{
    static void Main(string[] args)
    {
        File.WriteAllText("foo.txt", "test");
        File.Move("foo.txt", "Foo.txt"); //this throws
    }
}

This results in the following exception:

Unhandled Exception: System.IO.IOException: The file '/Users/Brandon/Code/repro2/Foo.txt' already exists.
   at System.IO.UnixFileSystem.MoveFile(String sourceFullPath, String destFullPath)
   at System.IO.File.Move(String sourceFileName, String destFileName)
   at repro2.Program.Main(String[] args) in /Users/Brandon/Code/repro2/Program.cs:line 11

This same program does not throw when run on Windows or linux, and instead results in the renamed Foo.txt on disk.

I would expect this to behave consistently across all platforms. Using mv foo.txt Foo.txt on macOS renames the file correctly, so I would expect the same thing to be possible via File.Move.

dotnet --info
.NET Command Line Tools (1.0.1)

Product Information:
 Version:            1.0.1
 Commit SHA-1 hash:  005db40cd1

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.12
 OS Platform: Darwin
 RID:         osx.10.12-x64
 Base Path:   /usr/local/share/dotnet/sdk/1.0.1