diff --git a/requirements-test.txt b/requirements-test.txt
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -3,3 +3,4 @@
 swh.core[http] >= 0.0.61
 swh.scheduler[testing] >= 0.5.0
 swh.storage[testing]
+pytest-postgresql >= 2.1.0, < 3.0
diff --git a/swh/loader/mercurial/from_disk.py b/swh/loader/mercurial/from_disk.py
--- a/swh/loader/mercurial/from_disk.py
+++ b/swh/loader/mercurial/from_disk.py
@@ -167,10 +167,6 @@
         # If set, will override the default value
         self._visit_status = None
 
-        self.old_environ = os.environ.copy()
-        os.environ.clear()
-        os.environ.update(get_minimum_env())
-
     def pre_cleanup(self) -> None:
         """As a first step, will try and check for dangling data to cleanup.
         This should do its best to avoid raising issues.
@@ -182,6 +178,10 @@
             log=self.log,
         )
 
+        self.old_environ = os.environ.copy()
+        os.environ.clear()
+        os.environ.update(get_minimum_env())
+
     def cleanup(self) -> None:
         """Last step executed by the loader."""
         os.environ.clear()
diff --git a/swh/loader/mercurial/tests/conftest.py b/swh/loader/mercurial/tests/conftest.py
--- a/swh/loader/mercurial/tests/conftest.py
+++ b/swh/loader/mercurial/tests/conftest.py
@@ -47,3 +47,4 @@
     """
     os.environ["HGPLAIN"] = ""
     os.environ["HGRCPATH"] = ""
+    os.environ["HGRCSKIPREPO"] = ""