Fix setuptools CI issue (#9400)

Co-authored-by: hauntsaninja <>

Author: hauntsaninja

.github/workflows/test.yml

@@ -42,7 +42,7 @@ jobs:
         python-version: ${{ matrix.python }}
         architecture: ${{ matrix.arch }}
     - name: install tox
-      run: pip install --upgrade setuptools 'virtualenv<20' tox==3.9.0
+      run: pip install --upgrade 'setuptools<50' 'virtualenv<20' tox==3.9.0
     - name: setup tox environment
       run: tox -e ${{ matrix.toxenv }} --notest
     - name: test

test-requirements.txt

@@ -12,5 +12,5 @@ pytest-cov>=2.10.0,<3.0.0
 typing>=3.5.2; python_version < '3.5'
 py>=1.5.2
 virtualenv<20
-setuptools
+setuptools<50
 importlib-metadata==0.20