Add a restore source to the artifacts/build folder and ensure build number is consistent when running local builds

build/sources.props

@@ -7,6 +7,10 @@
       $(DotNetAdditionalRestoreSources);
       $(DotNetRestoreSources);
     </RestoreSources>
+    <RestoreSources Condition="Exists('$(RepositoryRoot)artifacts/build/')">
+      $(RepositoryRoot)artifacts/build/;
+      $(DotNetRestoreSources);
+    </RestoreSources>
     <RestoreSources Condition=" '$(DotNetBuildOffline)' != 'true' ">
       $(RestoreSources);
       https://dotnetfeed.blob.core.windows.net/dotnet-core/index.json;

version.props

@@ -5,7 +5,7 @@
     <AspNetCorePatchVersion>0</AspNetCorePatchVersion>
     <PreReleaseLabel>rtm</PreReleaseLabel>
     <PreReleaseBrandingLabel></PreReleaseBrandingLabel>
-    <BuildNumber Condition="'$(BuildNumber)' == ''">$([System.DateTime]::Now.ToString('yyMMdd'))-99</BuildNumber>
+    <BuildNumber Condition="'$(BuildNumber)' == '' OR '$(UsingLocalBuildNumber)' == 'true'">$([System.DateTime]::Now.ToString('yyMMdd'))-99</BuildNumber>
     <VersionPrefix>$(AspNetCoreMajorVersion).$(AspNetCoreMinorVersion).$(AspNetCorePatchVersion)</VersionPrefix>
     <ExperimentalVersionPrefix>0.2.$(AspNetCorePatchVersion)</ExperimentalVersionPrefix>
     <VersionSuffix>$(PreReleaseLabel)-$(BuildNumber)</VersionSuffix>