use a virtualenv on Windows to fix dirty environment issues (#1121)

* try to use a virtualenv on Windows to fix dirty environment issues

* remove Python 3.6, add 3.9 on Windows

Author: beniwohli

.ci/.jenkins_windows.yml

@@ -6,15 +6,15 @@
 #
 
 windows:
-  - VERSION: "3.6"
-    WEBFRAMEWORK: "none"
-    ASYNCIO: "true"
+#  - VERSION: "3.6"
+#    WEBFRAMEWORK: "none"
+#    ASYNCIO: "true"
   - VERSION: "3.7"
     WEBFRAMEWORK: "none"
     ASYNCIO: "true"
   - VERSION: "3.8"
     WEBFRAMEWORK: "none"
     ASYNCIO: "true"
-#  - VERSION: "3.9"  # waiting for greenlet to have binary wheels for 3.9
-#    WEBFRAMEWORK: "none"
-#    ASYNCIO: "true"
+  - VERSION: "3.9"  # waiting for greenlet to have binary wheels for 3.9
+    WEBFRAMEWORK: "none"
+    ASYNCIO: "true"

scripts/install-tools.bat

@@ -8,6 +8,8 @@
 call "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\Common7\Tools\vsdevcmd.bat" -arch=amd64
 
 : We need wheel installed to build wheels
-call %PYTHON%\python.exe -m pip install -U wheel pip setuptools
-call %PYTHON%\python.exe -m pip install -r tests\requirements\reqs-%WEBFRAMEWORK%.txt
-call %PYTHON%\python.exe -m pip install psutil
+call %PYTHON%\python.exe -m venv "%cd%\venv"
+set VENV_PYTHON=%cd%\venv\Scripts\
+call %VENV_PYTHON%\python.exe -m pip install -U wheel pip setuptools
+call %VENV_PYTHON%\python.exe -m pip install -r tests\requirements\reqs-%WEBFRAMEWORK%.txt
+call %VENV_PYTHON%\python.exe -m pip install psutil

scripts/run-tests.bat

@@ -6,15 +6,17 @@
 @echo off
 
 @echo on
+set VENV_PYTHON=%cd%\venv\Scripts\
+
 set COVERAGE_FILE=.coverage.%VERSION%.%WEBFRAMEWORK%
 set IGNORE_PYTHON3_WITH_PYTHON2=
 if "%VERSION%" == "2.7" set IGNORE_PYTHON3_WITH_PYTHON2=--ignore-glob="*\py3_*.py"
 
 set PYTEST_JUNIT="--junitxml=.\tests\python-agent-junit.xml"
 if "%ASYNCIO%" == "true" (
-    %PYTHON%\python.exe -m pytest %PYTEST_JUNIT% %IGNORE_PYTHON3_WITH_PYTHON2% --cov --cov-context=test --cov-branch --cov-config=setup.cfg -m "not integrationtest" || exit /b 1
+    %VENV_PYTHON%\python.exe -m pytest %PYTEST_JUNIT% %IGNORE_PYTHON3_WITH_PYTHON2% --cov --cov-context=test --cov-branch --cov-config=setup.cfg -m "not integrationtest" || exit /b 1
 )
 if "%ASYNCIO%" == "false" (
-    %PYTHON%\python.exe -m pytest %PYTEST_JUNIT% --ignore-glob="*\asyncio*\*" %IGNORE_PYTHON3_WITH_PYTHON2% --cov --cov-context=test --cov-branch --cov-config=setup.cfg -m "not integrationtest" || exit /b 1
+    %VENV_PYTHON%\python.exe -m pytest %PYTEST_JUNIT% --ignore-glob="*\asyncio*\*" %IGNORE_PYTHON3_WITH_PYTHON2% --cov --cov-context=test --cov-branch --cov-config=setup.cfg -m "not integrationtest" || exit /b 1
 )
-call %PYTHON%\python.exe setup.py bdist_wheel
+call %VENV_PYTHON%\python.exe setup.py bdist_wheel