diff --git a/.circleci/config.yml b/.circleci/config.yml
index d803cbf2e..1c7464a1b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -63,6 +63,9 @@ jobs:
             ccache -z
             make
             ccache -s
+            # install all relevant pyodide_build files to
+            # the virtualenv that will be persisted
+            pip install .
 
       - save_cache:
           paths:
diff --git a/pyodide_build/pywasmcross.py b/pyodide_build/pywasmcross.py
index e2f5acd92..290b9ac14 100755
--- a/pyodide_build/pywasmcross.py
+++ b/pyodide_build/pywasmcross.py
@@ -223,7 +223,6 @@ def make_parser(parser):
     parser.add_argument(
         '--target', type=str, nargs='?', default=common.TARGETPYTHON,
         help='The path to the target Python installation')
-    parser.add_argument('basename', type=str, nargs='?')
     return parser
 
 
diff --git a/test/make_test_list.py b/test/make_test_list.py
index cfa548c39..b2d2a5cb3 100644
--- a/test/make_test_list.py
+++ b/test/make_test_list.py
@@ -7,7 +7,7 @@ from pathlib import Path
 
 
 TEST_DIR = (Path(__file__).parent
-            / "cpython/build/3.6.4/host/lib/python3.7/test")
+            / "cpython/build/3.7.0/host/lib/python3.7/test")
 
 
 def collect_tests(base_dir):
diff --git a/test/test_common.py b/test/test_common.py
index 1d5d0fd69..5f7fe60b3 100644
--- a/test/test_common.py
+++ b/test/test_common.py
@@ -1,15 +1,11 @@
 import pytest
 import os
 from pathlib import Path
-import sys
+from pyodide_build.common import parse_package
 
 BASE_DIR = Path(__file__).parent.parent
 PKG_DIR = BASE_DIR / 'packages'
 
-# TODO: remove once we have a proper Python package for common functions
-sys.path.append(str(BASE_DIR / 'tools'))
-import common  # noqa
-
 
 def registered_packages():
     """Returns a list of registred package names"""
@@ -23,7 +19,7 @@ def registered_packages_meta():
     for each registed package
     """
     packages = registered_packages
-    return {name: common.parse_package(PKG_DIR / name / 'meta.yaml')
+    return {name: parse_package(PKG_DIR / name / 'meta.yaml')
             for name in packages}
 
 
@@ -34,7 +30,7 @@ UNSUPPORTED_PACKAGES = {'chrome': ['pandas'],
 @pytest.mark.parametrize('name', registered_packages())
 def test_import(name, selenium_standalone):
     # check that we can parse the meta.yaml
-    meta = common.parse_package(PKG_DIR / name / 'meta.yaml')
+    meta = parse_package(PKG_DIR / name / 'meta.yaml')
 
     if name in UNSUPPORTED_PACKAGES[selenium_standalone.browser]:
         pytest.xfail(