Install requirements.txt with SETUPTOOLS_ENABLE_FEATURES=legacy-editable

This appears to be needed for passing CI now.  It’s not the best
solution and will probably stop working after a while, but at least it
will allow development to proceed for now.

Signed-off-by: Anders Kaseorg <[email protected]>

Author: andersk

.github/workflows/test.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Install dependencies
         run: |
           pip install -U pip setuptools wheel
-          pip install -r ./requirements.txt
+          SETUPTOOLS_ENABLE_FEATURES=legacy-editable pip install -r ./requirements.txt
 
       - name: Run pre-commit
         run: pre-commit install && pre-commit run --all-files
@@ -43,7 +43,7 @@ jobs:
       - name: Install dependencies
         run: |
           pip install -U pip setuptools wheel
-          pip install -r ./requirements.txt
+          SETUPTOOLS_ENABLE_FEATURES=legacy-editable pip install -r ./requirements.txt
 
       - name: Run tests
         run: pytest --mypy-ini-file=mypy.ini
@@ -68,7 +68,7 @@ jobs:
       - name: Install dependencies
         run: |
           pip install -U pip setuptools wheel
-          pip install -r ./requirements.txt
+          SETUPTOOLS_ENABLE_FEATURES=legacy-editable pip install -r ./requirements.txt
 
       - name: Run tests
         run: python ./scripts/typecheck_tests.py --django_version="${{ matrix.django-version }}"

CONTRIBUTING.md

@@ -43,7 +43,7 @@ source .venv/bin/activate
 Then install the dev requirements:
 
 ```bash
-pip install -r ./requirements.txt
+env SETUPTOOLS_ENABLE_FEATURES=legacy-editable pip install -r ./requirements.txt
 ```
 
 Finally, install the pre-commit hooks: