Could not load file or assembly System.CodeDom

Describe the bug I Updated from 0.3.1-beta to 0.5-beta and we got a exception in all our services ( linux/windows )

System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types.
Could not load file or assembly 'System.CodeDom, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
Could not load file or assembly 'System.CodeDom, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
   at System.Reflection.RuntimeModule.GetTypes(RuntimeModule module)
   at System.Reflection.RuntimeModule.GetTypes()
   at System.Reflection.Assembly.GetTypes()
   at flowfact.services.attributes.ServiceRegister.<>c__DisplayClass3_0.<FindTypesByAttribute>b__1(Assembly s)
   at System.Linq.Enumerable.WhereSelectArrayIterator`2.MoveNext()
   at System.Linq.Enumerable.SelectManySingleSelectorIterator2.ToList()
   at flowfact.services.attributes.ServiceRegister.FindTypesByAttribute(Type[] types)
System.IO.FileNotFoundException: Could not load file or assembly 'System.CodeDom, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.
File name: 'System.CodeDom, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'
System.IO.FileNotFoundException: Could not load file or assembly 'System.CodeDom, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The system cannot find the file specified.

File name: 'System.CodeDom, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'

Runtime environment (please complete the following information):

• Instrumentation mode: manual
• Tracer version: 0.5.0-beta
• OS: Linux / Docker image ( microsoft/dotnet:2.1-runtime-deps-stretch-slim )
• CLR: .Net Core 2.1

Additional context i dont know what the exact problem is, but i think this lines below does produce the error with 0.3.1-beta everythings works fine ( already did the downgrade ), with 0.5-beta i can reproduce the exception above

private static List<(Type Type, object[] CustomAttributes)> FindTypesByAttribute(params Type[] types)
{
    try
    {
        var allTypes = AppDomain.CurrentDomain.GetAssemblies()
            .Where(s => !s.FullName.StartsWith("Microsoft") && !s.FullName.StartsWith("System."))
            .Select(s => s.GetTypes()
                .Select(type => (Type: type, CustomAttributes: type.GetCustomAttributes(true)))
                .Where(z => z.CustomAttributes.Length > 0 && z.CustomAttributes.Any(t => types.Any(i => i == t.GetType())))
            );

        return allTypes.SelectMany(s => s).ToList();
    }
    catch (Exception ex)
    {
        Logger.Error(ex);
    }
    return null;
}

[lucaspimentel]

I created this PR so it can be fixed in the next release of their library.

[lucaspimentel]

It looks like the error is caused by a MsgPack.Cli dependency. In v0.4.0, we updated the MsgPack.Cli NuGet reference from 0.9.2 to 1.0.0 (see #158). MsgPack.Cli has a reference to System.CodeDom 4.4.0 which is not included in the nuspec file, so it doesn’t show up in their NuGet package.

This issue in their repo seems to be related.

In the short term, you can avoid the exception by skipping the MsgPack assembly in the LINQ query:

var allTypes = AppDomain.CurrentDomain
                        .GetAssemblies()
                        .Where(s => !s.FullName.StartsWith("Microsoft") &&
                                    !s.FullName.StartsWith("System.") &&
                                    !s.FullName.StartsWith("MsgPack"))   // skip MsgPack
                        .Select(s => s.GetTypes()