Fix crashes with higher verbosity levels

This was causing issues in running the test suite locally at higher
verbosity levels, since this block causes errors when passed a URL.

Author: pradyunsg

src/pip/_internal/index/package_finder.py

@@ -37,7 +37,6 @@
 from pip._internal.utils.misc import build_netloc
 from pip._internal.utils.packaging import check_requires_python
 from pip._internal.utils.unpacking import SUPPORTED_EXTENSIONS
-from pip._internal.utils.urls import url_to_path
 
 __all__ = ["FormatControl", "BestCandidateResult", "PackageFinder"]
 
@@ -816,7 +815,14 @@ def find_all_candidates(self, project_name: str) -> List[InstallationCandidate]:
         )
 
         if logger.isEnabledFor(logging.DEBUG) and file_candidates:
-            paths = [url_to_path(c.link.url) for c in file_candidates]
+            paths = []
+            for candidate in file_candidates:
+                assert candidate.link.url  # we need to have a URL
+                try:
+                    paths.append(candidate.link.file_path)
+                except Exception:
+                    paths.append(candidate.link.url)  # it's not a local file
+
             logger.debug("Local files found: %s", ", ".join(paths))
 
         # This is an intentional priority ordering