Troubleshoot file-in-use errors in 80+ project, multi-targetframework solution

[wouterroos]

Hi,

We're have a 80+ project multi-targetframework solution that leverages xml documentation, xmltransform and creates NuGet packages on build. Building this solution works fine most of the time. However, rebuilding the solution results in various types of 'file-in-use' errors, causing the rebuild to fail. A subsequent build usually is successful. Is there any way to troubleshoot these errors to see where they're coming from and fix them? These errors vary in that sometimes it's the xml documentation file that can't be deleted, sometimes it's an XmlTransform file. I've tried setting the msbuild output verbosity to diagnostic but I can't seem to find anything helpful. Setting msbuild's maxcpucount to 1 seems to prevent the issues. Due to the size of solution that isn't a feasible solution, but it does seem to hint to something to do with parallel builds causing the issue? The issue occurs both using msbuild.exe (16.11.2+f32259642) and Visual Studio (2019 and 2022). Please see below for an examples of the error's we're getting.

Thanks!

MSB3061 Unable to delete file "<OBJFOLDER>\<PACKAGEID>.3.0.0-debug.nuspec". Access to the path '<OBJFOLDER>\<PACKAGEID>.3.0.0-debug.nuspec' is denied. <PROJECTNAME> C:\Program Files\dotnet\sdk\6.0.100\Sdks\NuGet.Build.Tasks.Pack\build\NuGet.Build.Tasks.Pack.targets (Line 175)