Follow the proper Python instructions in https://docs.microsoft.com/en-us/azure/devops/pipelines/languages/python?view=azure-devops for our Azure Pipelines file.

azure-pipelines.yml

@@ -8,9 +8,15 @@ jobs:
   workspace:
     clean: all
   steps:
+  - task: UsePythonVersion@0
+    inputs:
+      versionSpec: '3.6'
+      architecture: 'x64'
   - script: |
-      sudo apt-get install -y libgtk-3-dev ninja-build python3-setuptools
+      apt-get install -y libgtk-3-dev ninja-build
-      sudo pip3 install meson
+      # Ubuntu typically comes with an outdated meson
+      python -m pip install --upgrade pip setuptools wheel
+      pip install meson
     displayName: 'Setup'
   - script: |
       meson setup build-shared --buildtype=release