Failed to load language 'IronPython 2.7.11': Value cannot be null. (Parameter 'path1') when producing single file

[newbienewbie]

Prerequisites

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Description

get an error of "Failed to load language 'IronPython 2.7.11': Value cannot be null. (Parameter 'path1')" when publishing a .net5.0 project with the "Produce Single File" option setting as True.

Steps to Reproduce

1. create a c# project using .NET 5 which targets net5.0
2. invoke Python as below:

    class Program
    {
        static void Main(string[] args)
        {
            RunScript();
        }

        static ScriptEngine scriptEngine = null;
        static ScriptScope scriptScope = null;

        static void RunScript()
        {
            if (scriptEngine is null)
            {
                scriptEngine = Python.CreateEngine();
                scriptScope = scriptEngine.CreateScope();
                scriptScope.SetVariable("Hello","World");
            }

            var source = scriptEngine.CreateScriptSourceFromString("print Hello");
            var code = source.Compile();
            code.Execute(scriptScope);
        }
    }

3. publish the project by

dotnet publish -c Release -r win-x64  --self-contained true -p:PublishSingleFile=true

run the published exe
Expected behavior: The above prints "World" succeessfully.

Actual behavior: I get an error as below

...\bin\Release\net5.0\win-x64\publish> .\TestIronPython.exe
Unhandled exception. System.Reflection.TargetInvocationException: Failed to load language 'IronPython 2.7.11': Value cannot be null. (Parameter 'path1')
 ---> System.ArgumentNullException: Value cannot be null. (Parameter 'path1')
   at System.IO.Path.Combine(String path1, String path2)
   at IronPython.Runtime.PythonContext..ctor(ScriptDomainManager manager, IDictionary`2 options)
   --- End of inner exception stack trace ---
   at Microsoft.Scripting.Runtime.LanguageConfiguration.LoadLanguageContext(ScriptDomainManager domainManager, Boolean& alreadyLoaded)
   at Microsoft.Scripting.Runtime.DlrConfiguration.LoadLanguageContext(ScriptDomainManager manager, LanguageConfiguration config)
   at Microsoft.Scripting.Runtime.DlrConfiguration.TryLoadLanguage(ScriptDomainManager manager, AssemblyQualifiedTypeName& providerName, LanguageContext& language)   at Microsoft.Scripting.Runtime.ScriptDomainManager.GetLanguageByTypeName(String providerAssemblyQualifiedTypeName)
   at Microsoft.Scripting.Hosting.ScriptRuntime.GetEngineByTypeName(String assemblyQualifiedTypeName)
   at IronPython.Hosting.Python.GetEngine(ScriptRuntime runtime)
   at IronPython.Hosting.Python.CreateEngine()
   at TestIronPython.Program.RunScript()
   at TestIronPython.Program.Main(String[] args)

Versions

You can get this information from executing ipy -V.

I'm not sure how to execute this command. I'm not invoking C# from python but instead invoking Python Script within a C# project.

• OS Version: Win10.0.19041:
• dotnet: 5.0.101

I'm using IronPython of 2.7.11

    <PackageReference Include="IronPython" Version="2.7.11" />

[slozier]

You are venturing in uncharted territories here. 😄 I'm guessing this is caused by an assembly location which is null when published as single file?