Fody exception in release mode. Symbol file .dll.mdb does not match the .dll assembly

Question

I am having trouble creating a PCL in Xamarin Studio on Mac. It works fine in debug mode, but fody throws an exception in Release mode.

An exception during assembly is shown below.

Error: Fody: An unhandled exception occurred: Exception: Symbol file `XXX/obj/Release/XXX.dll.mdb' does not match assembly `XXX/obj/Release/XXX.dll' StackTrace: at Mono.CompilerServices.SymbolWriter.MonoSymbolFile.CheckGuidMatch (Guid other, System.String filename, System.String assembly) [0x00000] in <filename unknown>:0 at Mono.CompilerServices.SymbolWriter.MonoSymbolFile..ctor (System.String filename, Mono.Cecil.ModuleDefinition module) [0x00000] in <filename unknown>:0 at Mono.CompilerServices.SymbolWriter.MonoSymbolFile.ReadSymbolFile (Mono.Cecil.ModuleDefinition module, System.String filename) [0x00000] in <filename unknown>:0 at Mono.Cecil.Mdb.MdbReaderProvider.GetSymbolReader (Mono.Cecil.ModuleDefinition module, System.String fileName) [0x00000] in <filename unknown>:0 at Mono.Cecil.ModuleReader.ReadSymbols (Mono.Cecil.ModuleDefinition module, Mono.Cecil.ReaderParameters parameters) [0x00000] in <filename unknown>:0 at Mono.Cecil.ModuleReader.CreateModuleFrom (Mono.Cecil.PE.Image image, Mono.Cecil.ReaderParameters parameters) [0x00000] in <filename unknown>:0 at Mono.Cecil.ModuleDefinition.ReadModule (System.IO.Stream stream, Mono.Cecil.ReaderParameters parameters) [0x00000] in <filename unknown>:0 at Mono.Cecil.ModuleDefinition.ReadModule (System.String fileName, Mono.Cecil.ReaderParameters parameters) [0x00000] in <filename unknown>:0 at InnerWeaver.ReadModule () [0x00000] in <filename unknown>:0 at InnerWeaver.Execute () [0x00000] in <filename unknown>:0 Source: Mono.Cecil.Mdb TargetSite: Void CheckGuidMatch(System.Guid, System.String, System.String) 

Answer 1

Fody needs debugging information (* .mdb file) associated with the output assembly to complete the weaving phase. The release of the assembly by default disables the Debug information field inside Assembly → Compiler in the project settings.

If this build option is set to None , disables debugging symbology and causes the mdb file to fail, therefore the Symbol file 'XXX/obj/Release/XXX.dll.mdb' does not match assembly XXX/obj/Release/XXX.dll exception Symbol file 'XXX/obj/Release/XXX.dll.mdb' does not match assembly XXX/obj/Release/XXX.dll .

Therefore, when creating projects in release mode, when Fody is integrated into the build process, you need to include Symbols only or Full :

Answer 2

You may already have one, but I would start with this if it were me:

• Right click on your solution.
• The properties
• Configuration Properties / Configuration

In the Configuration drop-down list in the upper left corner, verify that the Debug configuration (re: Platform | Build | Deploy) matches Release.