diff --git a/build.sh b/build.sh
index 07719b6552..9e13e4bd4a 100755
--- a/build.sh
+++ b/build.sh
@@ -278,7 +278,7 @@ msbuild_args[${#msbuild_args[*]}]="-p:_RunPack=$run_pack"
 msbuild_args[${#msbuild_args[*]}]="-p:_RunTests=$run_tests"
 
 # Disable downloading ref assemblies as a tarball. Use netfx refs from the Microsoft.NETFramework.ReferenceAssemblies NuGet package instead.
-KOREBUILD_SKIP_INSTALL_NETFX=1
+[ -z "${KOREBUILD_SKIP_INSTALL_NETFX:-}" ] && KOREBUILD_SKIP_INSTALL_NETFX=1
 
 set_korebuildsettings "$tools_source" "$DOTNET_HOME" "$repo_path" "$config_file" "$ci"
 
diff --git a/build/repo.props b/build/repo.props
index 7530abe0df..551cec3d86 100644
--- a/build/repo.props
+++ b/build/repo.props
@@ -15,8 +15,8 @@
 
     <SubmoduleRoot>$(RepositoryRoot)src\</SubmoduleRoot>
 
-    <ArtifactsShippingPackagesDir>$(ArtifactsDir)\packages\$(Configuration)\Shipping\</ArtifactsShippingPackagesDir>
-    <ArtifactsNonShippingPackagesDir>$(ArtifactsDir)\packages\$(Configuration)\NonShipping\</ArtifactsNonShippingPackagesDir>
+    <ArtifactsShippingPackagesDir>$(ArtifactsDir)packages\$(Configuration)\Shipping\</ArtifactsShippingPackagesDir>
+    <ArtifactsNonShippingPackagesDir>$(ArtifactsDir)packages\$(Configuration)\NonShipping\</ArtifactsNonShippingPackagesDir>
     <InstallersOutputPath>$(ArtifactsDir)installers\$(Configuration)\</InstallersOutputPath>
 
     <SignCheckExclusionsFile>$(RepositoryRoot)eng\signcheck.exclusions.txt</SignCheckExclusionsFile>
diff --git a/dockerbuild.sh b/dockerbuild.sh
index b34962846e..da76a9f482 100755
--- a/dockerbuild.sh
+++ b/dockerbuild.sh
@@ -26,6 +26,7 @@ __usage() {
     echo ""
     echo "Options:"
     echo "    -v, --volume <VOLUME>      An additional volume mount to add to the build container"
+    echo "    -e, --env <NAME=VAL>       Additional environment variables to add to the build container"
     echo ""
     echo "Description:"
     echo "    This will run build.sh inside the dockerfile as defined in build/docker/\$image.Dockerfile."
@@ -69,6 +70,13 @@ while [[ $# -gt 0 ]]; do
             docker_args[${#docker_args[*]}]="--volume"
             docker_args[${#docker_args[*]}]="$volume_spec"
             ;;
+        -e|--env)
+            shift
+            env_var="${1:-}"
+            [ -z "$env_var" ] && __error "Missing value for parameter --env" && __usage
+            docker_args[${#docker_args[*]}]="-e"
+            docker_args[${#docker_args[*]}]="$env_var"
+            ;;
         *)
             build_args[${#build_args[*]}]="$1"
             ;;
diff --git a/eng/Versions.props b/eng/Versions.props
index 08860f7f0c..b6df1478c9 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -110,7 +110,7 @@
   </PropertyGroup>
   <PropertyGroup Label="Build tool dependencies">
     <InternalAspNetCoreSdkPackageVersion>$(KoreBuildVersion)</InternalAspNetCoreSdkPackageVersion>
-    <InternalAspNetCoreSdkPackageVersion Condition=" '$(KoreBuildVersion)' == '' ">3.0.0-build-20190118.3</InternalAspNetCoreSdkPackageVersion>
+    <InternalAspNetCoreSdkPackageVersion Condition=" '$(KoreBuildVersion)' == '' ">3.0.0-build-20190118.4</InternalAspNetCoreSdkPackageVersion>
     <MicrosoftNETFrameworkReferenceAssembliesPackageVersion>1.0.0-alpha-004</MicrosoftNETFrameworkReferenceAssembliesPackageVersion>
     <MicrosoftNETTestSdkPackageVersion>15.9.0</MicrosoftNETTestSdkPackageVersion>
   </PropertyGroup>
diff --git a/global.json b/global.json
index 25f50308d7..4b78711287 100644
--- a/global.json
+++ b/global.json
@@ -3,6 +3,6 @@
     "version": "3.0.100-preview-009750"
   },
   "msbuild-sdks": {
-    "Internal.AspNetCore.Sdk": "3.0.0-build-20190118.3"
+    "Internal.AspNetCore.Sdk": "3.0.0-build-20190118.4"
   }
 }
diff --git a/korebuild-lock.txt b/korebuild-lock.txt
index 4a6c864eda..f48262d1e4 100644
--- a/korebuild-lock.txt
+++ b/korebuild-lock.txt
@@ -1,2 +1,2 @@
-version:3.0.0-build-20190118.3
-commithash:27bad0e40ebbb1b8f1d4b7143edc600974fbe3db
+version:3.0.0-build-20190118.4
+commithash:dc060235e4056a2a5ec0141fa89da9e490544268