mpc not parsing MessagePackObject contained in .Net Core class library projects correctly

[YuandongLi]

I tried to use mpc to generate resolvers for some of my classes marked with MessagePackObject attribute from a .Net Core class library project.
However, GeneratedResolverGetFormatterHelper.GetFormatter(Type) in the resulting file only contains an empty switch statement which is different from what I got by generating from a ,Net console application project.
When I built mpc from source and attached a debugger to it, I found that when generating from a .net Core class library project, it throws an exception. The exception indicates the constructor parameter is empty for MessagePackObjectAttribute and KeyAttribute when supplying with a csproj file from a .net Core class library project.
It looks like Roslyn fails to parse those construct parameters in this case.

Is there something you could do fix it? Thanks!

[Rurouni]

Feels similar to #23
I don't think author can easily fix that issue because MSBuildWorkspace is not working as it should yet dotnet/roslyn#17974

[YuandongLi]

@Rurouni Agree. Just wonder if the author has any workarounds in mind though.

[neuecc]

Thank you.
I do not have expectations for updating MSBuildWorkspace.
It is necessary to migrate that can be handled itself.
But it need a little more time.

[neuecc]

support for mono, set Environment path, it works for new csproj, etc.
252e6db

[neuecc]

related to #188 and close(discussion move).