CI: use python 3.7.x

Author: compnerd

.azure-pipelines.yml

@@ -66,10 +66,24 @@ jobs:
         echo "##vso[task.setvariable variable=LLVM_NM]$(rustc --print sysroot)\\lib\\rustlib\\x86_64-pc-windows-msvc\\bin\\llvm-nm.exe"
       displayName: Find llvm-nm (Windows)
       condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))
+    - task: UsePythonVersion@0
+      inputs:
+        versionSpec: 3.7
+        addToPath: true
+      displayName: Select Python
+      name: python
+    - bash: |
+        echo "##vso[task.setvariable variable=PYTHON]$(python.pythonLocation)/python"
+      displayName: Find Python (!Windows)
+      condition: and(succeeded(), not(eq(variables['Agent.OS'], 'Windows_NT')))
+    - script: |
+        echo ##vso[task.setvariable variable=PYTHON]$(python.pythonLocation)\python.exe
+      displayName: Find Python (Windows)
+      condition: and(succeeded(), eq(variables['Agent.OS'], 'Windows_NT'))
     - task: CMake@1
       inputs:
         workingDirectory: $(Build.BinariesDirectory)
-        cmakeArgs: -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_SYSTEM_NAME=Generic -DCMAKE_AR=$(LLVM_AR) -DCMAKE_NM=$(LLVM_NM) -DCMAKE_C_COMPILER=clang -S $(Build.SourcesDirectory)
+        cmakeArgs: -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_SYSTEM_NAME=Generic -DCMAKE_AR=$(LLVM_AR) -DCMAKE_NM=$(LLVM_NM) -DCMAKE_C_COMPILER=clang -DPython_EXECUTABLE=$(PYTHON) -S $(Build.SourcesDirectory)
       displayName: Configure
     - task: CMake@1
       inputs: