v5.5.0b9 - Crash when processing Microsoft.CodeAnalysis.Workspaces.dll

I created a new project, added a new script containing "using Microsoft.CodeAnalysis.MSBuild" and the line "MSBuildWorkspace ws = MSBuildWorkspace.Create()". I add the file Microsoft.CodeAnalysis.Workspaces.Desktop.dll to the Assets folder and switch focus to Unity which successfully processes it.

Then I add Microsoft.CodeAnalysis.Workspaces.Desktop.dll to the assets folder, switch focus to Unity which starts processing it and crashes according to the attached crashdump.

Both managed assemblies are compiled against .NET Runtime v4.0.30319 and are of version 1.3.1.0.

 

Attaching Editor.log. Can also see an empty file named "CrashedAssetImports.txt" in the project Library folder, if that helps.

 

Created bug tracker issue https://fogbugz.unity3d.com/default.asp?846041_h6f74h657vp55c3c
Forgot to attach files and can't seem to acquire a login.