Speed up Ninja downloading on Mac.

azure-pipelines.yml

@@ -336,9 +336,7 @@ jobs:
   steps:
   - template: azure-pipelines/setup-python3.yml
   - template: azure-pipelines/install-latest-meson.yml
-  - script: |
-      brew install ninja
-    displayName: 'Install Dependencies'
+  - template: azure-pipelines/darwin-install-ninja.yml
   - template: azure-pipelines/configure.yml
     parameters:
       beforeConfigure: export SDKROOT=$(xcodebuild -version -sdk macosx10.12 Path)

azure-pipelines/darwin-install-ninja.yml

@@ -0,0 +1,12 @@
+# 5 april 2019
+# because brew install is also slow (it runs an update task first)
+
+steps:
+- script: |
+    sudo mkdir /opt/ninja
+    pushd /opt/ninja
+    sudo wget https://github.com/ninja-build/ninja/releases/download/v1.9.0/ninja-mac.zip
+    sudo unzip ninja-mac.zip
+    popd
+    echo '##vso[task.prependpath]/opt/ninja'
+  displayName: 'Install Ninja'