Linux – Mono uses mscorlib.dll 2.0 instead of 4.0

I’m having trouble with a MONO app, I’m trying to compile the project (using MonoDevelop) in order to load the library to run mscorlib.dll 4.0 instead of version 2.0. (I need the System.Type.op_Equality method, it’s in version 4.0 but not in version 2.0).

I solved it for the time being via the link :

# cd /usr/lib/mono/2.0
# mv mscorlib.dll mscorlib.dll.bak
# ln .. /4.0/mscorlib.dll mscorlib.dll

But this is certainly not an effective solution.

Does anyone know how MONO loads mscorlib 4.0 instead of 2.0?

Thanks and sorry for my English

Finally I found a solution to this problem :

https://bugs.launchpad.net/ubuntu/+source/gtk-sharp2/+bug/884035/comments/14

Just modify the “app.config” file and change the contents:

<?xml version="1.0"?>
<configuration>
<startup><supportedRuntime version="v4.0"/></startup></configuration>

Recompile the project and it now works.