os.rename() fails on Windows if file already exists

BetsyMcPhail · BetsyMcPhail · commit 73985a252dee · 2021-02-10T09:44:11.000-05:00
diff --git a/lib/spack/spack/database.py b/lib/spack/spack/database.py
@@ -978,6 +978,11 @@ def _write(self, type, value, traceback):
         try:
             with open(temp_file, 'w') as f:
                 self._write_to_file(f)
+            # On Windows, os.rename will fail if the destination file
+            # already exists
+            if sys.platform == "win32":
+                if os.path.exists(self._index_path):
+                    os.remove(self._index_path)
             os.rename(temp_file, self._index_path)
             if _use_uuid:
                 with open(self._verifier_path, 'w') as f:
diff --git a/lib/spack/spack/util/file_cache.py b/lib/spack/spack/util/file_cache.py
@@ -5,6 +5,7 @@
 
 import os
 import shutil
+from sys import platform as _platform
 
 from llnl.util.filesystem import mkdirp
 
@@ -145,6 +146,11 @@ def __exit__(cm, type, value, traceback):  # noqa
                     shutil.rmtree(cm.tmp_filename, True)
 
                 else:
+                    # On Windows, os.rename will fail if the destination file
+                    # already exists
+                    if _platform == "win32":
+                        if os.path.exists(cm.orig_filename):
+                            os.remove(cm.orig_filename)
                     os.rename(cm.tmp_filename, cm.orig_filename)
 
         return WriteTransaction(
