How does csc/Roslyn resolve assembly version?

Question

I have a console program that has two direct dependencies: ClosedXML v0.97 and ClosedXML.Report 0.2.4. The ClosedXML.Report dependency also depends on ClosedXML, but in a version 0.95.

When I try to compile the program in NET6 (basically only a reference to a class in the ClosedXml.Report),

_ = new XLTemplate(new System.IO.MemoryStream());

I get a compiler error

CS0012 The type 'IXLWorkbook' is defined in an assembly that is not referenced. You must add a reference to assembly 'ClosedXML, Version=0.95.0.0, Culture=neutral, PublicKeyToken=null'.

Why doesn't csc.exe recognize the 0.97 version to use and requests 0.95 (the indirect dependency)? The assembly version of package is same as the nuget version.

Nuget uses direct-dependency-wins mechanism and I though .net core also uses that for assemlby resolution. Is a mechanism different? How does roslyn resolve which version to use and when to throw an error?

Relevant piece of MSBuild

C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Current\Bin\Roslyn\csc.exe 
/reference:C:\Users\username\.nuget\packages\closedxml\0.97.0\lib\netstandard2.0\ClosedXML.dll
/reference:C:\Users\username\.nuget\packages\closedxml.report\0.2.4\lib\netstandard2.0\ClosedXML.Report.dll 

Answer 1

One possible explanation for this behavior would be if IXLWorkbook, which is apparently required by the call to new XLTemplate() no longer exists in Version 0.97 of ClosedXML.

If possible, try to rebuild ClosedXML.Report with ClosedXML 0.97. Since these apparently are early versions (Version < 1.0) breaking changes between versions seem possible. Also, can you make sure that the output bin directory actually contains Version 0.97?