another shot at redirecting stderr

scripts/common.ps1

@@ -27,7 +27,7 @@ function Invoke-CmdScript {
       [String] $scriptName
     )
     $cmdLine = """$scriptName"" $args & set"
-    & $Env:SystemRoot\system32\cmd.exe /c $cmdLine 2>&1 |
+    & $Env:SystemRoot\system32\cmd.exe /c $cmdLine |
     select-string '^([^=]*)=(.*)$' | foreach-object {
       $varName = $_.Matches[0].Groups[1].Value
       $varValue = $_.Matches[0].Groups[2].Value
@@ -43,7 +43,7 @@ function Invoke-Call {
         [scriptblock]$ScriptBlock,
         [string]$ErrorAction = $ErrorActionPreference
     )
-    & @ScriptBlock
+    & @ScriptBlock 2>&1 | %{ "$_" }
     if (($lastexitcode -ne 0) -and $ErrorAction -eq "Stop") {
         Write-Error "Command $ScriptBlock exited with $lastexitcode."
         exit $lastexitcode

scripts/git_checkout.ps1

@@ -12,17 +12,27 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+. ${PSScriptRoot}\common.ps1
+
 Set-PSDebug -Trace 1
 
+# Wrap git commant in error handling function
+function Invoke-Git
+{
+    param (
+        [scriptblock]$args
+    )
+    Invoke-Call -ScriptBlock { git $args } -ErrorAction Stop
+}
+
 if (Test-Path -PathType Container "llvm-project"){
     Set-Location llvm-project
     Write-Output "performing git pull..."
-    git checkout master 2>&1 | %{ "$_" }
-    git reset --hard 2>&1 | %{ "$_" }
-    git clean -fdx 2>&1 | %{ "$_" }
-    git pull 2>&1 | %{ "$_" }
+    Invoke-Git checkout master
+    Invoke-Git reset
+    Invoke-Git clean -fdx
+    Invoke-Git pull
     # TODO: in case of errors: delete folder and clone
 } else {
     Write-Output "performing git clone..."
-    git clone -q --depth 1 https://github.com/llvm/llvm-project 2>&1 | %{ "$_" }
-}
+    Invoke-Git clone -q --depth 1 https://github.com/llvm/llvm-project

scripts/run_cmake.ps1

@@ -20,9 +20,14 @@ Push-Location build
 
 Invoke-CmdScript "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\Common7\Tools\VsDevCmd.bat" -arch=amd64 -host_arch=amd64
 
-# Invoke-Call -ScriptBlock { 
-cmake ..\llvm -G Ninja -DCMAKE_BUILD_TYPE=Release         -D LLVM_ENABLE_PROJECTS="clang;clang-tools-extra"         -D LLVM_ENABLE_ASSERTIONS=ON         -DLLVM_LIT_ARGS="-v --xunit-xml-output test-results.xml"         -D LLVM_ENABLE_DIA_SDK=OFF --trace 2>&1 | %{ "$_" }
-#} -ErrorAction Stop
+Invoke-Call -ScriptBlock {
+  cmake ..\llvm -G Ninja -DCMAKE_BUILD_TYPE=Release  `
+         -D LLVM_ENABLE_PROJECTS="clang;clang-tools-extra" `
+         -D LLVM_ENABLE_ASSERTIONS=ON `
+         -DLLVM_LIT_ARGS="-v --xunit-xml-output test-results.xml" `
+         -D LLVM_ENABLE_DIA_SDK=OFF `
+         --trace
+} -ErrorAction Stop
 
 # LLVM_ENABLE_DIA_SDK=OFF is a workaround to make the tests pass.
 # see https://bugs.llvm.org/show_bug.cgi?id=44151