Make unpacking remove target directory, if it exists from previous failed installation

usr/lib/python3.8/spoc/repo_online.py

@@ -3,6 +3,7 @@
 import json
 import os
 import requests
+import shutil
 import tarfile
 import time
 from cryptography.exceptions import InvalidSignature
@@ -57,9 +58,15 @@ def unpack_archive(archive_path, destination, expected_hash, observer):
         # Verify file object, then seek back and open it as tar without losing handle, preventing possible malicious race conditions
         verify_fileobj(f, expected_hash)
         f.seek(0)
-        tar = tarfile.open(fileobj=f)
+        # Remove the target directory, if it exists from previous failed installation
+        dst_dir = os.path.join(destination, os.path.basename(archive_path)[:-7])
+        try:
+            shutil.rmtree(dst_dir)
+        except FileNotFoundError:
+            pass
         # Extract the tar members while counting their size
         # If this is done as non-root, extractall() from https://github.com/python/cpython/blob/master/Lib/tarfile.py needs to be reimplemented instead
+        tar = tarfile.open(fileobj=f)
         for tarinfo in tar:
             tar.extract(tarinfo, destination, numeric_owner=True)
             observer.units_done += tarinfo.size