Allow skipping virtual environment tests

This is useful for tox end ensurepip tests for pypy 2.7.

smoke/venv.sh

@@ -36,11 +36,20 @@ elif [ "$METHOD" == "virtualenv-no-download" ]; then
   virtualenv --no-download --python=$PYTHON venv
 elif [ "$METHOD" == "virtualenv-seeder-pip" ]; then
   virtualenv --seeder pip --python=$PYTHON venv
+elif [ "$METHOD" == "none" ]; then
+  echo 'Skipping plain virtual environment tests' >&2
 else
   echo 'Unsupported $METHOD' $METHOD >&2
 exit 1
 fi
 
+# create tests
+cat > test_foo.py << EOF
+def test_foo():
+    assert True
+EOF
+
+if [ "$METHOD" != "none" ]; then
 
 # and activate it
 # unset variables on 3.5, it's known
@@ -55,11 +64,6 @@ python -c 'import sys; print(sys.version)' | head -n1 | grep ${VERSION/t}
 python -m pip install pytest
 
 # run tests
-cat > test_foo.py << EOF
-def test_foo():
-    assert True
-EOF
-
 python -m pytest -v test_foo.py
 
 if [ "$CYTHON" == "true" ]; then
@@ -96,6 +100,8 @@ set +u
 deactivate
 set -u
 
+fi # METHOD != none
+
 # ensurepip test (when testing virtualenv, this was not covered)
 # with the main Python, this will say "Requirement already satisfied", but that's OK
 $PYTHON -m ensurepip --root ensurepiptestroot

tests.yml

@@ -56,7 +56,7 @@
         run: VERSION=3.10 METHOD=virtualenv-download TOX=false ./venv.sh
     - smokepypy:
         dir: smoke
-        run: runuser testuser -c 'VERSION=2.7 METHOD=virtualenv PYTHON=pypy ./venv.sh'
+        run: runuser testuser -c 'VERSION=2.7 METHOD=none PYTHON=pypy TOX_REQUIRES="virtualenv<20.22.0" ./venv.sh'
     - smokepypy39:
         dir: smoke
         run: runuser testuser -c 'VERSION=3.9 METHOD=venv PYTHON=pypy3.9 ./venv.sh'