Workaround for pip's change in behavior

.circleci/config.yml

@@ -21,7 +21,7 @@ jobs:
  name: Install dependencies
  command: |
  virtualenv venv
- venv/bin/pip install $(grep black requirements_dev.txt | cut -d';' -f 1)
+ venv/bin/pip install --no-use-pep517 $(grep black requirements_dev.txt | cut -d';' -f 1)
  - run:
  name: Run black
  command: |
@@ -81,7 +81,7 @@ jobs:
  name: Install Python dependencies
  command: |
  virtualenv venv
- venv/bin/pip install -r requirements_dev.txt
+ venv/bin/pip install --no-use-pep517 -r requirements_dev.txt
  - run:
  name: Install sfdx
  command: |
@@ -136,7 +136,7 @@ jobs:
  name: Install Python dependencies
  command: |
  virtualenv venv
- venv/bin/pip install -r requirements_dev.txt
+ venv/bin/pip install --no-use-pep517 -r requirements_dev.txt
  - run:
  name: Check out CumulusCI-Test
  command: |

CONTRIBUTING.rst

@@ -57,7 +57,7 @@ Ready to contribute? Here's how to set up CumulusCI for local development.
 2. Clone your fork to your local workspace.
 3. Create a fresh virtual environment using virtualenv and install development requirements::
 
- $ pip install -r requirements_dev.txt
+ $ pip install --no-use-pep517 -r requirements_dev.txt
 
 4. Install ``pre-commit`` hooks for ``black`` and ``flake8``::
 

tox.ini

@@ -7,7 +7,5 @@ setenv =
 
 commands = coverage run {envbindir}/pytest []
 
-; If you want to make tox run the tests with the same versions, create a
-; requirements.txt with the pinned versions and uncomment the following lines:
-deps =
- -r{toxinidir}/requirements_dev.txt
+install_command =
+ python -m pip install --no-use-pep517 -r {toxinidir}/requirements_dev.txt