copy .nupkg to nuget store without overwrite

 Best solution (to copy to .csproj file)
 - Runs after packing
 - RoboCopy needs space after path arg e.g "..\df sd " if path has spaces in it otherwise do not include space.
 - /XO ignores newer files in source
 - /NFL /NDL /NJH partially removes RoboCopy output
 - Since RoboCopy had different exit codes than MSBuild and many don't indicate error; need last two lines
 
  <Target Name="PostPack" AfterTargets="Pack">
    <Exec Command="
      set source=&quot;$(ProjectDir)$(OutDir).. &quot;&#xD;&#xA;
      set target=&quot;..\NugetPackages &quot;  &#xD;&#xA;
      RoboCopy %25source%25 %25target%25 *.nupkg  /XO  /NFL /NDL /NJH   &#xD;&#xA;
      IF %ERRORLEVEL% GEQ 8 exit 1&#xD;&#xA;
      exit 0" />
  </Target>

Won't work
xcopy will overwrite files if they were generated on different dates

dotnet pack --no-build --output nupkgs --include-source --include-symbols
set store="<name of nuget package store directory>"
for %%f in ("$(ProjectDir)$(OutDir)..\*.nupkg") do xcopy %%f %store%  /Y /I /D


or alternativaly
  <Target Name="PostPack" AfterTargets="Pack">
    <Exec Command="&#xD;&#xA;set store=&quot;<name of nuget package store directory>&quot;&#xD;&#xA;for %25%25f in (&quot;$(ProjectDir)$(OutDir)..\*.nupkg&quot;) do  xcopy %25%25f %25store%25  /Y /I /D" />
  </Target>

robocopy c:\Sourcepath c:\Destpath /E /XC /XN /XO

:: /E makes Robocopy recursively copy subdirectories, including empty ones.
:: /XC excludes existing files with the same timestamp, but different file sizes. Robocopy normally overwrites those.
:: /XN excludes existing files newer than the copy in the source directory. Robocopy normally overwrites those.
:: /XO excludes existing files older than the copy in the source directory. Robocopy normally overwrites those.
:: With the Changed, Older, and Newer classes excluded, Robocopy will exclude files existing in the destination directory.