I was hoping to add some contributions to the project but have trouble with your non standard build system.
I've installed nuproj but there are various errors after building. For example.

the project references are broken. I get the following warnings
Severity Code Description Project File Line Suppression State
Warning The project 'ImmutableObjectGraph' cannot be referenced. ImmutableObjectGraph.Generation
Warning The project 'ImmutableObjectGraph.Generation.Attributes' cannot be referenced. ImmutableObjectGraph.Generation
Warning The project 'ImmutableObjectGraph.Generation.Attributes' cannot be referenced. ImmutableObjectGraph.Generation.Tests
Warning The project 'ImmutableObjectGraph' cannot be referenced. ImmutableObjectGraph.Generation.Tests
Warning The project 'ImmutableObjectGraph' cannot be referenced. RoslynDemo
Warning The project 'ImmutableObjectGraph.Generation.Attributes' cannot be referenced. RoslynDemo
Warning The "Nerdbank.GitVersioning.Tasks.GetBuildVersion" task failed unexpectedly.
System.MissingMethodException: Method not found: 'System.IO.Stream LibGit2Sharp.Blob.GetContentStream()'.
at Nerdbank.GitVersioning.VersionFile.GetVersionFileReader(Commit commit, String repoRelativeProjectDirectory, Boolean& isJsonFile)
at Nerdbank.GitVersioning.VersionFile.GetVersion(Commit commit, String repoRelativeProjectDirectory)
at Nerdbank.GitVersioning.GitExtensions.IsVersionFileChangedInWorkingCopy(Repository repo, String repoRelativeProjectDirectory, VersionOptions& committedVersion, VersionOptions& workingCopyVersion)
at Nerdbank.GitVersioning.GitExtensions.GetVersionHeight(Repository repo, String repoRelativeProjectDirectory)
at Nerdbank.GitVersioning.Tasks.GetBuildVersion.Execute()
at Microsoft.Build.BackEnd.TaskExecutionHost.Microsoft.Build.BackEnd.ITaskExecutionHost.Execute()
at Microsoft.Build.BackEnd.TaskBuilder.<ExecuteInstantiatedTask>d__26.MoveNext() RoslynDemo C:\Users\phelan\.nuget\packages\Nerdbank.GitVersioning\1.4.41\build\Nerdbank.GitVersioning.targets 44
When I try to look at the project properties for ImmutableObjectGraph(Portable) I see the following error.

My colleauge thinks this has something to do with the "suppresParent" field in the project.json file but we are not sure what removing this field might do to the build.
I was hoping to add some contributions to the project but have trouble with your non standard build system.
I've installed nuproj but there are various errors after building. For example.
the project references are broken. I get the following warnings
When I try to look at the project properties for ImmutableObjectGraph(Portable) I see the following error.
My colleauge thinks this has something to do with the "suppresParent" field in the project.json file but we are not sure what removing this field might do to the build.