More iterating on a problem.

.github/workflows/ci.yaml

@@ -96,7 +96,7 @@ jobs:
           git submodule sync
           git submodule update --init --recursive
           python -m pip install -e . --upgrade
-          pipenv install --deploy --dev --python=${{ steps.python-path.outputs.path }}
+          pipenv --system-site-packages install --deploy --dev --python=${{ steps.python-path.outputs.path }}
       - name: Run tests
         env:
           PIPENV_DEFAULT_PYTHON_VERSION: ${{ matrix.python-version }}

pipenv/core.py

@@ -1371,7 +1371,7 @@ def get_pip_args(
         "upgrade": ["--upgrade"],
         "require_hashes": ["--require-hashes"],
         "no_build_isolation": ["--no-build-isolation"],
-        "no_use_pep517": [],
+        "no_use_pep517": ["--no-use-pep517"],
         "no_deps": ["--no-deps"],
         "selective_upgrade": [
             "--upgrade-strategy=only-if-needed",
@@ -1379,8 +1379,6 @@ def get_pip_args(
         ],
         "src_dir": src_dir,
     }
-    # TODO: Why do we use no pep517?
-    arg_map["no_use_pep517"].append("--no-use-pep517")
     arg_set = []
     for key in arg_map.keys():
         if key in locals() and locals().get(key):