Import Error while running pytest in virtualenv

I am trying to run my pytest (bdd) test cases in virtualenv. I have created a requirements.txt (using pip freeze) file in the root folder as below.

apipkg==1.5 atomicwrites==1.3.0 attrs==19.1.0 behave==1.2.6 certifi==2019.6.16 chardet==3.0.4 chromedriver==2.24.1 contextlib2==0.6.0.post1 coverage==4.5.4 docker==4.2.0 execnet==1.7.1 extras==1.0.0 Faker==4.1.1 fixtures==3.0.0 fuzzywuzzy==0.17.0 glob2==0.7 html-testRunner==1.2 html2text==2020.1.16 HTMLParser==0.0.2 idna==2.8 imaplib2==2.45.0 importlib-metadata==0.23 Jinja2==2.9.5 lettuce==0.2.23 lettuce-webdriver==0.3.5 linecache2==1.0.0 Mako==1.1.0 MarkupSafe==1.1.1 mock==3.0.5 more-itertools==7.0.0 packaging==19.2 parse==1.11.1 parse-type==0.4.2 path==15.0.0 path.py==12.5.0 pbr==5.4.2 pi==0.1.2 pipenv==2018.11.26 pluggy==0.13.0 py==1.8.0 pyparsing==2.4.2 pyperclip==1.7.0 PyQt5==5.13.0 PyQt5-sip==4.19.18 PyQtWebEngine==5.13.0 pytest==5.1.2 pytest-bdd==3.2.1 pytest-docker-fixtures==1.3.6 pytest-fixture-config==1.7.0 pytest-forked==1.1.3 pytest-html==2.0.0 pytest-metadata==1.8.0 pytest-ordering==0.6 pytest-shutil==1.7.0 pytest-splinter==2.0.1 pytest-virtualenv==1.7.0 pytest-xdist==1.31.0 pytest-yield==1.0.0 python-dateutil==2.8.1 python-mimeparse==1.6.0 python-subunit==1.3.0 PyYAML==5.3.1 QScintilla==2.11.2 requests==2.22.0 responses==0.10.9 selenium==3.141.0 six==1.12.0 splinter==0.11.0 sure==1.4.11 termcolor==1.1.0 testtools==2.3.0 text-unidecode==1.3 traceback2==1.4.0 unittest2==1.1.0 urllib3==1.24.1 virtualenv==16.7.2 virtualenv-clone==0.5.3 wcwidth==0.1.7 websocket-client==0.57.0 zipp==0.6.0 

I have created the virtual env, activated the same and installed the dependencies using the below commands.

virtualenv test source test/bin/activate pip install -r requirements.txt 

However when I am trying to run the test cases, am getting the below errors.

Traceback (most recent call last): File "/test/bin/pytest", line 8, in <module> sys.exit(main()) File "/test/lib/python3.7/site-packages/_pytest/config/__init__.py", line 59, in main config = _prepareconfig(args, plugins) File "/test/lib/python3.7/site-packages/_pytest/config/__init__.py", line 209, in _prepareconfig pluginmanager=pluginmanager, args=args File "/test/lib/python3.7/site-packages/pluggy/hooks.py", line 286, in __call__ return self._hookexec(self, self.get_hookimpls(), kwargs) File "/test/lib/python3.7/site-packages/pluggy/manager.py", line 92, in _hookexec return self._inner_hookexec(hook, methods, kwargs) File "/test/lib/python3.7/site-packages/pluggy/manager.py", line 86, in <lambda> firstresult=hook.spec.opts.get("firstresult") if hook.spec else False, File "/test/lib/python3.7/site-packages/pluggy/callers.py", line 203, in _multicall gen.send(outcome) File "/test/lib/python3.7/site-packages/_pytest/helpconfig.py", line 89, in pytest_cmdline_parse config = outcome.get_result() File "/test/lib/python3.7/site-packages/pluggy/callers.py", line 80, in get_result raise ex[1].with_traceback(ex[2]) File "/test/lib/python3.7/site-packages/pluggy/callers.py", line 187, in _multicall res = hook_impl.function(*args) File "/test/lib/python3.7/site-packages/_pytest/config/__init__.py", line 720, in pytest_cmdline_parse self.parse(args) File "/test/lib/python3.7/site-packages/_pytest/config/__init__.py", line 928, in parse self._preparse(args, addopts=addopts) File "/test/lib/python3.7/site-packages/_pytest/config/__init__.py", line 874, in _preparse self.pluginmanager.load_setuptools_entrypoints("pytest11") File "/test/lib/python3.7/site-packages/pluggy/manager.py", line 297, in load_setuptools_entrypoints plugin = ep.load() File "/test/lib/python3.7/site-packages/importlib_metadata/__init__.py", line 92, in load module = import_module(match.group('module')) File "/test/lib/python3.7/importlib/__init__.py", line 127, in import_module return _bootstrap._gcd_import(name[level:], package, level) File "<frozen importlib._bootstrap>", line 1006, in _gcd_import File "<frozen importlib._bootstrap>", line 983, in _find_and_load File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked File "<frozen importlib._bootstrap>", line 677, in _load_unlocked File "/test/lib/python3.7/site-packages/_pytest/assertion/rewrite.py", line 140, in exec_module exec(co, module.__dict__) File "/test/lib/python3.7/site-packages/pytest_yield/plugin.py", line 11, in <module> from _pytest.python import Generator ImportError: cannot import name 'Generator' from '_pytest.python' (/test/lib/python3.7/site-packages/_pytest/python.py) 

Can you help me understand what I am missing here? I tried with different versions of pytest, without luck. However the test cases are running fine in my local without any issues.