Fix the coverage tracking nox session

This session now correctly handles tracking coverage and running tests.

1 files changed, 11 insertions, 3 deletions

diff --git a/noxfile.py b/noxfile.py
index 9de795fe5..b7d3d8253 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -229,15 +229,23 @@ def vendoring(session: nox.Session) -> None:
 
 @nox.session
 def coverage(session: nox.Session) -> None:
-    if not os.path.exists("./.coverage-output"):
-        os.mkdir("./.coverage-output")
+    # Install source distribution
+    run_with_protected_pip(session, "install", ".")
+
+    # Install test dependencies
+    run_with_protected_pip(session, "install", "-r", REQUIREMENTS["tests"])
+
+    if not os.path.exists(".coverage-output"):
+        os.mkdir(".coverage-output")
     session.run(
         "pytest",
         "--cov=pip",
         "--cov-config=./setup.cfg",
+        *session.posargs,
         env={
             "COVERAGE_OUTPUT_DIR": "./.coverage-output",
-            "COVERAGE_PROCESS_START": "./setup.cfg",
+            "COVERAGE_PROCESS_START": os.fsdecode(Path("setup.cfg").resolve()),
+            "SETUPTOOLS_USE_DISTUTILS": "stdlib",
         },
     )