From 154dbc597544b60bc4b090c1f85e828e7709c8d0 Mon Sep 17 00:00:00 2001
From: Niklas Schulze <me@jns.io>
Date: Fri, 27 Jul 2018 23:29:21 +0200
Subject: [PATCH] update_dart_sdk.ps1: Fall back to Invoke-WebRequest if BITS
 fails (#19873)

---
 bin/internal/update_dart_sdk.ps1 | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/bin/internal/update_dart_sdk.ps1 b/bin/internal/update_dart_sdk.ps1
index 405dbddebb1..f194a3434e9 100644
--- a/bin/internal/update_dart_sdk.ps1
+++ b/bin/internal/update_dart_sdk.ps1
@@ -43,8 +43,15 @@ if (Test-Path $dartSdkPath) {
 }
 New-Item $dartSdkPath -force -type directory | Out-Null
 $dartSdkZip = "$cachePath\$dartZipName"
-Import-Module BitsTransfer
-Start-BitsTransfer -Source $dartSdkUrl -Destination $dartSdkZip
+
+Try {
+    Import-Module BitsTransfer
+    Start-BitsTransfer -Source $dartSdkUrl -Destination $dartSdkZip
+}
+Catch {
+    Write-Host "Downloading the Dart SDK using the BITS service failed, retrying with WebRequest..."
+    Invoke-WebRequest -Uri $dartSdkUrl -OutFile $dartSdkZip
+}
 
 Write-Host "Unzipping Dart SDK..."
 If (Get-Command 7z -errorAction SilentlyContinue) {