diff --git a/build.cmd b/build.cmd
index 38cc18707..2919f73b1 100644
--- a/build.cmd
+++ b/build.cmd
@@ -13,7 +13,7 @@ echo Build and run a subset of test suites
 echo.
 echo Usage:
 echo.
-echo build.cmd ^<all^|proto^|build^|debug^|release^|compiler^|coreclr^|pcls^|vs^|ci^|ci_part1^|ci_part2^>
+echo build.cmd ^<all^|proto^|build^|debug^|release^|diag^|compiler^|coreclr^|pcls^|vs^|ci^|ci_part1^|ci_part2^>
 echo.
 echo No arguments default to 'build' 
 echo.
@@ -33,6 +33,8 @@ set BUILD_PORTABLE=0
 set BUILD_VS=0
 set BUILD_CONFIG=release
 set BUILD_CONFIG_LOWERCASE=release
+set BUILD_DIAG=
+set BUILD_LOG=con
 
 set TEST_COMPILERUNIT=0
 set TEST_NET40_COREUNIT=0
@@ -75,6 +77,11 @@ if /i '%ARG%' == 'vs' (
     set TEST_VS=1
 )
 
+if /i '%ARG%' == 'diag' (
+    set BUILD_DIAG=/v:diag
+    set BUILD_LOG=fsharp_build_log.log
+)
+
 if /i '%ARG%' == 'all' (
     set BUILD_PROTO=1
     set BUILD_NET40=1
@@ -293,7 +300,7 @@ if '%BUILD_PROTO%' == '1' (
     @if ERRORLEVEL 1 echo Error: NGen of proto failed  && goto :failure
 )
 
-%_msbuildexe% %msbuildflags% build-everything.proj /p:Configuration=%BUILD_CONFIG%
+%_msbuildexe% %msbuildflags% build-everything.proj /p:Configuration=%BUILD_CONFIG% %BUILD_DIAG% >%BUILD_LOG%
 @if ERRORLEVEL 1 echo Error: '%_msbuildexe% %msbuildflags% build-everything.proj /p:Configuration=%BUILD_CONFIG%' failed && goto :failure
 
 @echo on
diff --git a/src/FSharpSource.targets b/src/FSharpSource.targets
index 0eff1823f..f6d429bd9 100644
--- a/src/FSharpSource.targets
+++ b/src/FSharpSource.targets
@@ -797,9 +797,6 @@
     
     <NuGetPackagesPath Condition="'$(NuGetPackagesPath)' == ''">$(FSharpSourcesRoot)\..\packages</NuGetPackagesPath>
 
-    <!-- fix this to be not so unfortunate looking -->
-    <BuildToolsDir>$(MSBuildThisFileDirectory)..\Tools\</BuildToolsDir>
-
     <!-- Implicitly needed by packageresolve.targets.  Should file a bug for a better error message here -->
     <PackagesDir>$(NuGetPackagesPath)\</PackagesDir>
 
@@ -820,7 +817,7 @@
          so we ignore the pre-calculation in the lock file and calculate asset applicability in the build task -->
     <NuGetIngoreLockFile>true</NuGetIngoreLockFile>
   </PropertyGroup>
-  <Import  Condition="'$(TargetFramework)'=='coreclr'" Project="$(BuildToolsDir)Build.Common.Targets" />
+  <Import  Condition="'$(TargetFramework)'=='coreclr'" Project="$(BuildToolsTaskDir)\Build.Common.Targets" />
 
   <PropertyGroup>
     <!-- Hook compilation phase to do custom work -->