add restorenocache environment variable when building in CI to avoid … (#6237)

* add restorenocache environment variable when building in CI to avoid restore issues with the http cache

Author: riarenas

Diff for: eng/common/tools.ps1

@@ -540,13 +540,15 @@ function GetDefaultMSBuildEngine() {
 
 function GetNuGetPackageCachePath() {
   if ($env:NUGET_PACKAGES -eq $null) {
-    # Use local cache on CI to ensure deterministic build,
+    # Use local cache on CI to ensure deterministic build. 
+    # Avoid using the http cache as workaround for https://github.com/NuGet/Home/issues/3116
     # use global cache in dev builds to avoid cost of downloading packages.
     # For directory normalization, see also: https://github.com/NuGet/Home/issues/7968
     if ($useGlobalNuGetCache) {
       $env:NUGET_PACKAGES = Join-Path $env:UserProfile '.nuget\packages\'
     } else {
       $env:NUGET_PACKAGES = Join-Path $RepoRoot '.packages\'
+      $env:RESTORENOCACHE = $true
     }
   }
 

Diff for: eng/common/tools.sh

@@ -312,12 +312,14 @@ function InitializeBuildTool {
   _InitializeBuildToolFramework="netcoreapp2.1"
 }
 
+# Set RestoreNoCache as a workaround for https://github.com/NuGet/Home/issues/3116
 function GetNuGetPackageCachePath {
   if [[ -z ${NUGET_PACKAGES:-} ]]; then
     if [[ "$use_global_nuget_cache" == true ]]; then
       export NUGET_PACKAGES="$HOME/.nuget/packages"
     else
       export NUGET_PACKAGES="$repo_root/.packages"
+      export RESTORENOCACHE=true
     fi
   fi