Interop is no more static, so we have to provide an instance to SetValue... Oops!

SharpPhysFS/Interop.cs

@@ -249,7 +249,7 @@ namespace SharpPhysFS
         var funcPtr = loadSymbol(library, field.Name);
         var del = Marshal.GetDelegateForFunctionPointer(funcPtr, field.FieldType);
 
-        field.SetValue(null, del);
+        field.SetValue(this, del);
       }
     }
   }

Test/Program.cs

@@ -291,7 +291,9 @@ namespace Test
         Console.WriteLine("Usage: cat <file>");
         return false;
       }
-      using (var reader = new System.IO.StreamReader(physFS.OpenRead(args[0])))
+
+      using (var stream = physFS.OpenRead(args[0]))
+      using (var reader = new System.IO.StreamReader(stream))
       {
         Console.WriteLine(reader.ReadToEnd());
       }