.NET 7.0 compatibility, Failed to find dll "DlibDotNetNative", for processor architecture AMD64

[gallianne]

Summary of your issue

I got the Following exception at runtime System.Exception: 'Failed to find dll "DlibDotNetNative", for processor architecture AMD64.'
Is there any known limitation on .Net 7.0 ?

Environment

.NET 7.0 on a WPF application running on windows 11 with a x64 build
DlibDotNetNative.dll and DlibDotNetNativeDnn.dll are in [projectFolder]\bin\x64\Debug\net7.0-windows10.0.17763.0\runtimes\win-x64\native and are both x64 dll
DlibDotNet.dll is in [projectFolder]\bin\x64\Debug\net7.0-windows10.0.17763.0

What did you do when you faced the problem?

It crash at runtime as soon as i call a DlibDotNet method

Output:

System.Exception: 'Failed to find dll "DlibDotNetNative", for processor architecture AMD64.'

What did you intend to be?

DlibDotNet seams to work on an empty .NET 7 application but Always crash in my Solution.
I would like know if there is a know limitation with .NET 7.0 x64 build for windows.

Thanks a lot

[Megadino]

I also faced this issue and found that a path where Dlib searches for native assemblies depends on run conditions.

If I have .NET 6 Core Console app, and run it in Debug mode with VS attached or run as stand-alone from CMD, everything works as expected.

But then I have .NET Core desktop WinForms app, and this is where the fun begins. If I run the app stand-alone, all works and Dlib looks for native Dlls in the folder [projectFolder]\bin\x64\Debug\net7.0-windows10.0.17763.0\runtimes\win-x64\native

If I run that desktop Winforms app from VS with the attached debugger, then suddenly, Dlib looks for native DLLs in the folder
[projectFolder]\bin\x64\Debug\net7.0-windows10.0.17763.0\dll\x64

How did I find that - I used the ProcessMonitor app to track all disk activity of my app and saw that it looks for Dlib native DLLs in that weird '\dll\x64' path.

[gallianne]

Thanks @Megadino ! It solved my issue.

[jonathanmcnamee]

I'm facing this glitch too, is there an neat fix?

[jonathanmcnamee]

Looking at the decompiled version of WindowsLibraryLoader

I can see there there are multiple loading strategies. If the class wasn't sealed we could override it - can you provide an overload for this method so we can provide additional relative directories?

namespace DlibDotNet;

internal sealed class WindowsLibraryLoader

private void LoadLibrary(string dllName)
{
	if (!IsCurrentPlatformSupported())
	{
		return;
	}
	try
	{
		lock (_SyncLock)
		{
			if (LoadedLibraries.ContainsKey(dllName))
			{
				return;
			}
			ProcessArchitectureInfo processArchitecture = GetProcessArchitecture();
			string directoryName = Path.GetDirectoryName(GetType().GetTypeInfo().Assembly.Location);
			if (LoadLibraryInternal(dllName, directoryName, processArchitecture) != IntPtr.Zero)
			{
				return;
			}
			directoryName = AppContext.BaseDirectory;
			if (LoadLibraryInternal(dllName, directoryName, processArchitecture) != IntPtr.Zero)
			{
				return;
			}
			directoryName = Path.GetFullPath(Directory.GetCurrentDirectory());
			if (LoadLibraryInternal(dllName, directoryName, processArchitecture) != IntPtr.Zero)
			{
				return;
			}
			StringBuilder stringBuilder = new StringBuilder();
			stringBuilder.Append("Failed to find dll \"" + dllName + "\", for processor architecture " + processArchitecture.Architecture + ".");
			if (processArchitecture.HasWarnings)
			{
				stringBuilder.Append("\r\nWarnings: \r\n" + processArchitecture.WarningText());
			}
			throw new Exception(stringBuilder.ToString());
		}
	}
	catch (Exception)
	{
	}
}

[jonathanmcnamee]

my hacky fix for now - call this before you start facial recognition

`private void CopyNativeLibraries()
{
string binPath = Path.GetFullPath(AppContext.BaseDirectory);
string expectedFilePath = Path.Combine(binPath, @"dll\x64");
string otherPath = @"runtimes\win-x64\native";

    if (!Directory.Exists(expectedFilePath))
    {
        Directory.CreateDirectory(expectedFilePath);
    }




    DirectoryInfo otherDir = new DirectoryInfo(Path.Combine(binPath, otherPath));
    if (otherDir.Exists)
    {
        foreach (FileInfo file in otherDir.GetFiles())
        {
            string destFile = expectedFilePath + file.Name;
            if (!file.Exists || !File.Exists(destFile))
            {
                File.Copy(file.FullName, destFile);
                continue;
            }
        }
    }
}`