Can run program with Mono but not with Visual Studio Mac

Question

So I have a C# program that I'm making in Visual Studio Mac 2019. It uses the SFML.Net framework which depends on a dynamic library: libcsfml-graphics.2.5.0.dylib . Internally, the framework has a method called sfRenderWindow_createUnicode(...) . This method uses a DLLImport for CSFML.graphics . If I run the program in Visual Studio, I get a DllNotFoundException with message csfml-graphics .

In my global config file for Mono, I have a DLL Mapping:

<dllmap dll="csfml-graphics" target="libcsfml-graphics.2.5.0.dylib" />

After adding that, if I run my program in Visual Studio, I still get a DllNotFoundException . However , the message now says libcsfml-graphics.2.5.0.dylib . So it's looking for the right library but can't find it? The .dylib file is in the same folder as the .exe .

The weird part is I can run the program from the terminal like so:

MONO_LOG_LEVEL=debug MONO_LOG_MASK=dll mono hello-csharp.exe > log.txt

The log.txt file contains the following lines:

Mono: DllImport attempting to load: 'libcsfml-graphics.2.5.0.dylib'.
Mono: DllImport loaded library '/Users/rutvik/Desktop/hello-csharp/hello-csharp/bin/Debug/libcsfml-graphics.2.5.0.dylib'.
Mono: DllImport searching in: 'libcsfml-graphics.2.5.0.dylib' ('/Users/rutvik/Desktop/hello-csharp/hello-csharp/bin/Debug/libcsfml-graphics.2.5.0.dylib').
Mono: Searching for 'sfRenderWindow_createUnicode'.
Mono: Probing 'sfRenderWindow_createUnicode'.
Mono: Found as 'sfRenderWindow_createUnicode'.

So it can find the .dylib for some reason. What is Visual Studio Mac doing differently? And how do I configure it to make it work?

For reference, here is otool -L run against libcsfml-graphics.2.5.0.dylib :

libcsfml-graphics.2.5.0.dylib:
    libcsfml-graphics.2.5.dylib (compatibility version 2.5.0, current version 2.5.0)
    @rpath/sfml-graphics.framework/Versions/2.5.1/sfml-graphics (compatibility version 2.5.0, current version 2.5.1)
    @rpath/sfml-window.framework/Versions/2.5.1/sfml-window (compatibility version 2.5.0, current version 2.5.1)
    @rpath/sfml-system.framework/Versions/2.5.1/sfml-system (compatibility version 2.5.0, current version 2.5.1)
    /usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 400.9.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1252.50.4)

WHAT WORKED IN THE END:

Just to summarize, I put all the .dylib files in /usr/local/lib . The trick was to set the platform target to x64 as specified in the accepted answer. The DYLD_LIBRARY_PATH environment actually turned out to be not needed at all. And the .dylib files do not have to be in the same folder as the .exe .

Now both running from Visual Studio and running with mono in the terminal yield identical results.

Hooray!

Answer 1

1) Make sure your Platform Target matches your ABI type (x32 or x64 bit):

VS4M will launch the 32-bit Mono version by default as most project targets default to x32 . Of course this does not matter if you are producing "fat" dylibs.

2) Set DYLD_LIBRARY_PATH in your Run Configuration to match your dylib location:

re: https://www.mono-project.com/docs/advanced/pinvoke/#macos-framework-and-dylib-search-path