diff --git a/Library/Homebrew/dev-cmd/tap-new.rb b/Library/Homebrew/dev-cmd/tap-new.rb
index 7c5b0ad4e2..d43c059e18 100644
--- a/Library/Homebrew/dev-cmd/tap-new.rb
+++ b/Library/Homebrew/dev-cmd/tap-new.rb
@@ -55,10 +55,11 @@ module Homebrew
       jobs:
       - job: macOS
         pool:
-          vmImage: xcode9-macos10.13
+          vmImage: macOS-10.13
         steps:
           - bash: |
-              sudo xcode-select --switch /Applications/Xcode_10.app/Contents/Developer
+              set -e
+              sudo xcode-select --switch /Applications/Xcode_10.1.app/Contents/Developer
               brew update
               HOMEBREW_TAP_DIR="/usr/local/Homebrew/Library/Taps/#{tap}"
               mkdir -p "$HOMEBREW_TAP_DIR"
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 8a06007867..c21e217b42 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -4,6 +4,7 @@ jobs:
     vmImage: macOS-10.13
   steps:
     - bash: |
+        set -e
         sudo xcode-select --switch /Applications/Xcode_10.1.app/Contents/Developer
         HOMEBREW_REPOSITORY="$(brew --repo)"
         mv "$HOMEBREW_REPOSITORY/Library/Taps" "$PWD/Library"
@@ -36,6 +37,7 @@ jobs:
     vmImage: ubuntu-16.04
   steps:
     - bash: |
+        set -e
         HOMEBREW_REPOSITORY=/home/linuxbrew/.linuxbrew
         sudo mkdir -p /home/linuxbrew
         sudo mv "$PWD" "$HOMEBREW_REPOSITORY"