Findout Dll Dependency, System.dll and Mono.Security.dll

Unity includes Mono.Security.dll and System.dll as of 4.2.2f1.

Upgraded from 4.2 to 4.3.0f4 but still have Mono.Security.dll and System.dll in build. Tested a empty project and they are not included.

So most likely I have some script depending on them.

In order to find them, I deleted System reference in Mono as stated in this Answer, but rebuilding succeeded.

Is there any other way to find which script depend on System.dll?

Use ildasm.exe (at least, on windows, monodis is similar on mono platform: http://mono-project.com/Dis/Assembling_CIL_Code).

C:\Program Files (x86)\Microsoft SDKs\Windows\v7.0A\Bin\ildasm.exe

I recommend to “Dump Tree” (File menu) to a test file, then search for the referenced assembly (“[System]”) or namespace. It will show you the class and probably the method referencing the assembly.

As of 4.3, you don’t have to care about
“[System.Core]System.Runtime.CompilerServices.ExtensionAttribute”
which is caused by using extension methods. This is not a “real” reference, and you can use your build without System.Core.dll.