message: Fix python on Ubuntu 18.04 hosts
diff: @@ -284,7 +284,10 @@ functions:
  fi
  export CMAKE=${cmake}
  - python -m virtualenv venv
  + if ! python -m virtualenv venv 2>/dev/null; then
  + /opt/mongodbtoolchain/v3/bin/python3 -m venv venv
  + fi
  +
  cd venv
  if [ -f bin/activate ]; then
  . bin/activate
  