diff --git a/swh/loader/core/utils.py b/swh/loader/core/utils.py
--- a/swh/loader/core/utils.py
+++ b/swh/loader/core/utils.py
@@ -1,12 +1,18 @@
-# Copyright (C) 2018-2021  The Software Heritage developers
+# Copyright (C) 2018-2022  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 
+import io
 import os
 import shutil
+import signal
+import time
+import traceback
+from typing import Callable
 
+from billiard import Process, Queue  # type: ignore
 import psutil
 
 
@@ -43,3 +49,57 @@
         except Exception as e:
             if log:
                 log.warn("Fail to clean dangling path %s: %s", path_to_cleanup, e)
+
+
+class CloneTimeout(Exception):
+    pass
+
+
+class CloneFailure(Exception):
+    pass
+
+
+def _clone_task(clone_func: Callable, errors: Queue) -> None:
+    try:
+        clone_func()
+    except Exception as e:
+        exc_buffer = io.StringIO()
+        traceback.print_exc(file=exc_buffer)
+        errors.put_nowait(exc_buffer.getvalue())
+        raise e
+
+
+def clone_with_timeout(
+    src: str, dest: str, clone_func: Callable, timeout: float
+) -> None:
+    """Clone a repository with timeout.
+
+    Args:
+        src: clone source
+        dest: clone destination
+        clone_func: callable that does the actual cloning
+        timeout: timeout in seconds
+    """
+    errors: Queue = Queue()
+    process = Process(target=_clone_task, args=(clone_func, errors))
+    process.start()
+    process.join(timeout)
+
+    if process.is_alive():
+        process.terminate()
+        # Give it literally a second (in successive steps of 0.1 second),
+        # then kill it.
+        # Can't use `process.join(1)` here, billiard appears to be bugged
+        # https://github.com/celery/billiard/issues/270
+        killed = False
+        for _ in range(10):
+            time.sleep(0.1)
+            if not process.is_alive():
+                break
+        else:
+            killed = True
+            os.kill(process.pid, signal.SIGKILL)
+        raise CloneTimeout(src, timeout, killed)
+
+    if not errors.empty():
+        raise CloneFailure(src, dest, errors.get())