error propagation

Author: compnerd

utils/build-windows-toolchain.bat

@@ -25,8 +25,9 @@ echo set SKIP_UPDATE_CHECKOUT=%SKIP_UPDATE_CHECKOUT%>> %TEMP%\call-build.cmd
 echo set REPO_SCHEME=%REPO_SCHEME%>> %TEMP%\call-build.cmd
 echo "%~f0">> %TEMP%\call-build.cmd
 start /i /b /wait cmd.exe /env=default /c "%TEMP%\call-build.cmd"
+set ExitCode=%ErrorLevel%
 del %TEMP%\call-build.cmd
-exit /b
+exit /b %ExitCode%
 
 :Start