diff --git a/swh/loader/svn/replay.py b/swh/loader/svn/replay.py
--- a/swh/loader/svn/replay.py
+++ b/swh/loader/svn/replay.py
@@ -631,6 +631,9 @@
         path = root_path if root_path else self.path
         fullpath = os.path.join(path, external_path)
 
+        if self.editor.debug:
+            logger.debug("Removing external path %s", fullpath)
+
         # decrement number of references for external path when we really remove it
         # (when remove_subpaths is False, we just cleanup the external path before
         # copying exported paths in it)
diff --git a/swh/loader/svn/tests/test_externals.py b/swh/loader/svn/tests/test_externals.py
--- a/swh/loader/svn/tests/test_externals.py
+++ b/swh/loader/svn/tests/test_externals.py
@@ -1703,3 +1703,98 @@
         type="svn",
     )
     check_snapshot(loader.snapshot, loader.storage)
+
+
+def test_loader_with_unparsable_external_on_path(
+    swh_storage, repo_url, external_repo_url, tmp_path
+):
+    # first commit on external
+    add_commit(
+        external_repo_url,
+        "Create some directories and files in an external repository",
+        [
+            CommitChange(
+                change_type=CommitChangeType.AddOrUpdate,
+                path="code/hello/hello-world",
+                properties={"svn:executable": "*"},
+                data=b"#!/bin/bash\necho Hello World !",
+            ),
+            CommitChange(
+                change_type=CommitChangeType.AddOrUpdate,
+                path="code/foo/foo.sh",
+                properties={"svn:executable": "*"},
+                data=b"#!/bin/bash\necho foo",
+            ),
+        ],
+    )
+
+    # first commit
+    add_commit(
+        repo_url,
+        (
+            "Set parsable svn:externals property on project1 path of repository to load."
+            "Add a code directory with a file in it."
+        ),
+        [
+            CommitChange(
+                change_type=CommitChangeType.AddOrUpdate,
+                path="project1/",
+                properties={
+                    "svn:externals": (
+                        f"{svn_urljoin(external_repo_url, 'code/hello')} hello\n"
+                    )
+                },
+            ),
+            CommitChange(
+                change_type=CommitChangeType.AddOrUpdate,
+                path="code/foo.sh",
+                properties={"svn:executable": "*"},
+                data=b"#!/bin/bash\necho foo",
+            ),
+        ],
+    )
+
+    # second commit
+    add_commit(
+        repo_url,
+        (
+            "Set unparsable svn:externals property on project2 path of repository to load."
+        ),
+        [
+            CommitChange(
+                change_type=CommitChangeType.AddOrUpdate,
+                path="project2/",
+                properties={"svn:externals": ("^code/foo foo\n")},
+            ),
+        ],
+    )
+
+    # third commit
+    add_commit(
+        repo_url,
+        (
+            "Fix unparsable svn:externals property on project2 path of repository to load."
+        ),
+        [
+            CommitChange(
+                change_type=CommitChangeType.AddOrUpdate,
+                path="project2/",
+                properties={"svn:externals": ("^/code/foo foo\n")},
+            ),
+        ],
+    )
+
+    loader = SvnLoader(
+        swh_storage,
+        repo_url,
+        temp_directory=tmp_path,
+        check_revision=1,
+    )
+    assert loader.load() == {"status": "eventful"}
+    assert_last_visit_matches(
+        loader.storage,
+        repo_url,
+        status="full",
+        type="svn",
+    )
+    check_snapshot(loader.snapshot, loader.storage)
diff --git a/swh/loader/svn/tests/test_utils.py b/swh/loader/svn/tests/test_utils.py
--- a/swh/loader/svn/tests/test_utils.py
+++ b/swh/loader/svn/tests/test_utils.py
@@ -479,3 +479,16 @@
     assert (
         utils.parse_external_definition(external, dir_path, repo_url) == expected_result
     )
+
+
+@pytest.mark.parametrize(
+    "invalid_external",
+    [
+        "^tests@21 tests",
+    ],
+)
+def test_parse_invalid_external_definition(invalid_external):
+    with pytest.raises(ValueError, match="Failed to parse external definition"):
+        utils.parse_external_definition(
+            invalid_external, "/trunk/externals", "http://svn.example.org/repo"
+        )
diff --git a/swh/loader/svn/utils.py b/swh/loader/svn/utils.py
--- a/swh/loader/svn/utils.py
+++ b/swh/loader/svn/utils.py
@@ -310,6 +310,10 @@
         except ValueError:
             # handle URL like http://user@svn.example.org/
             pass
+
+    if not external_url or not path:
+        raise ValueError(f"Failed to parse external definition '{external}'")
+
     return (path.rstrip("/"), external_url, revision, relative_url)
 
 
@@ -329,6 +333,7 @@
     Returns:
         Whether the external definition is recursive
     """
+    assert external_url
     parsed_origin_url = urlparse(origin_url)
     parsed_external_url = urlparse(external_url)
     external_url = urlunparse(