Add debugging output for failing coverage test

Author: BrianMichell

noxfile.py

@@ -120,13 +120,16 @@ def tests(session: Session) -> None:
 @session(python=python_versions[0])
 def coverage(session: Session) -> None:
     """Produce the coverage report."""
-    args = session.posargs or ["report"]
+    args = session.posargs or ["report", "--debug=pathmap"]
 
     session.run("uv", "pip", "install", "coverage[toml]", external=True)
 
     if not session.posargs and any(Path().glob(".coverage.*")):
         session.run("coverage", "combine", external=True)
-
+    
+    # Add a debug command to see what files coverage is tracking
+    session.run("coverage", "debug", "data", external=True)
+    
     session.run("coverage", *args, external=True)