[IronPython] Compile IronPython Script to EXE on Linux

Dino Viehland dinov at microsoft.com
Mon Apr 26 22:27:30 CEST 2010

Ben wrote:
> OS: Ubuntu 9.10 using IronPython PPA
> https://launchpad.net/~gezakovacs/+archive/ironpython
> IronPython Version: IronPython 2.6 Beta 2 DEBUG ( on .NET
> 2.0.50727.1433
> Mono Version: Mono JIT compiler version 2.4.4 (Debian
> 2.4.4~svn151842-1gezakovacs~karmic1)
> I'm having trouble compiling any IronPython script to EXE on Linux.
> The scripts compile fine on IronPython2.6 on Windows. The DLL
> generated by the script before the exe step seems correct.
> I am using the pyc.exe script downloaded from:
> http://ironpython.codeplex.com/sourcecontrol/network/Show?projectName=IronPyth
> on&changeSetId=65328#991948
> I am using a command like: ipy pyc.exe /main:hello.py /target:exe
> The error is: SystemError: Method is not VarArgs method and optional
> types were passed
> And it comes on this line:    gen.EmitCall(OpCodes.Call,
> clr.GetClrType(Assembly).GetMethod("GetEntryAssembly"), ())
> The simplest example script is:
> import clr
> print "Hello world"

This looks like a Mono bug but it appears to be fixed in the latest version of Mono.  

This small program demonstrates the issue:

using System;
using System.Reflection;
using System.Reflection.Emit;

class Test {
    public static void Main(string[] args) {
        var asm = AppDomain.CurrentDomain.DefineDynamicAssembly(new AssemblyName("test"), AssemblyBuilderAccess.Save);
        var mod = asm.DefineDynamicModule("test.dll");
        var type = mod.DefineType("Test");
        var method = type.DefineMethod("TestMethod", MethodAttributes.Public | MethodAttributes.Static);
        var ilgen = method.GetILGenerator();
        ilgen.EmitCall(OpCodes.Call, typeof(Assembly).GetMethod("GetEntryAssembly"), new Type[0]);

Mono ( reports:

Unhandled Exception: System.InvalidOperationException: Method is not VarArgs method and optional types were passed
  at System.Reflection.Emit.ILGenerator.EmitCall (OpCode opcode, System.Reflection.MethodInfo methodInfo, System.Type[] optionalParameterTypes) [0x00000]
  at Test.Main (System.String[] args) [0x00000]

Even though the argument array of types is empty.  But it works just fine on Mono 2.6.3 for me.

If you can't/don't want to upgrade Mono you can change the EmitCall line to:

        ilgen.Emit(OpCodes.Call, typeof(Assembly).GetMethod("GetEntryAssembly"));

And it works fine.  The similar change to pyc should be:

	gen.Emit(OpCodes.Call, clr.GetClrType(Assembly).GetMethod("GetEntryAssembly"))

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