diff --git a/swh/loader/mercurial/hgutil.py b/swh/loader/mercurial/hgutil.py
--- a/swh/loader/mercurial/hgutil.py
+++ b/swh/loader/mercurial/hgutil.py
@@ -154,16 +154,20 @@
 
     if process.is_alive():
         process.terminate()
-        # Give it a second (literally), then kill it
+        # 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)
+        step = 0.1
+        for _ in range(11):
+            print(f"sleep {step} second")
+            time.sleep(step)
             if not process.is_alive():
+                print("process not alive, break")
                 break
         else:
             killed = True
+            print(f"process {process.pid} to stop: killed=={killed}")
             os.kill(process.pid, signal.SIGKILL)
         raise CloneTimeout(src, timeout, killed)
 
diff --git a/swh/loader/mercurial/tests/test_hgutil.py b/swh/loader/mercurial/tests/test_hgutil.py
--- a/swh/loader/mercurial/tests/test_hgutil.py
+++ b/swh/loader/mercurial/tests/test_hgutil.py
@@ -9,18 +9,24 @@
 from mercurial import hg  # type: ignore
 import pytest
 
+from swh.scheduler.utils import utcnow
+
 from .. import hgutil
 
 
 def test_clone_timeout(monkeypatch):
     src = "https://www.mercurial-scm.org/repo/hello"
     dest = "/dev/null"
-    timeout = 0.1
+    timeout = 1
+    sleepy_time = 10 * timeout
+    assert sleepy_time > timeout
 
-    def clone(*args, **kwargs):
+    def clone(*args, sleepy_time=sleepy_time, **kwargs):
         # ignore SIGTERM to force sigkill
         signal.signal(signal.SIGTERM, lambda signum, frame: None)
-        time.sleep(2)
+        print(f"(false clone) {utcnow()} Sleep for {sleepy_time} seconds.")
+        time.sleep(sleepy_time)  # we make sure we exceed the timeout
+        print(f"(false clone) {utcnow()} Slept but this should never get printed!")
 
     monkeypatch.setattr(hg, "clone", clone)