pygit2: Raise NotImplementedError on ssh remotes.

src/scmrepo/git/__init__.py

@@ -327,18 +327,12 @@ def fetch_refspecs(
         progress: Optional[Callable[["GitProgressEvent"], None]] = None,
         **kwargs,
     ) -> typing.Mapping[str, SyncStatus]:
-        from urllib.parse import urlparse
-
         from .credentials import get_matching_helper_commands
 
-        if "dulwich" in kwargs.get("backends", self.backends.backends):
-            credentials_helper = any(
-                get_matching_helper_commands(url, self.dulwich.repo.get_config_stack())
-            )
-            parsed = urlparse(url)
-            ssh = parsed.scheme in ("git", "git+ssh", "ssh") or url.startswith("git@")
-            if credentials_helper or ssh:
-                kwargs["backends"] = ["dulwich"]
+        if "dulwich" in kwargs.get("backends", self.backends.backends) and any(
+            get_matching_helper_commands(url, self.dulwich.repo.get_config_stack())
+        ):
+            kwargs["backends"] = ["dulwich"]
 
         return self._fetch_refspecs(
             url,

src/scmrepo/git/backend/pygit2.py

@@ -16,6 +16,7 @@
     Tuple,
     Union,
 )
+from urllib.parse import urlparse
 
 from funcy import cached_property, reraise
 from shortuuid import uuid
@@ -460,7 +461,8 @@ def get_remote(self, url: str) -> Generator["Remote", None, None]:
         except KeyError:
             raise SCMError(f"'{url}' is not a valid Git remote or URL")
 
-        if os.name == "nt" and url.startswith("ssh://"):
+        parsed = urlparse(url)
+        if parsed.scheme in ("git", "git+ssh", "ssh") or url.startswith("git@"):
             raise NotImplementedError
         if os.name == "nt" and url.startswith("file://"):
             url = url[len("file://") :]

tests/test_pygit2.py

@@ -1,3 +1,4 @@
+# pylint: disable=unused-argument
 import pygit2
 import pytest
 from pytest_mock import MockerFixture
@@ -58,3 +59,17 @@ def test_pygit_stash_apply_conflicts(
         strategy=expected_strategy,
         reinstate_index=False,
     )
+
+
+@pytest.mark.parametrize(
+    "url",
+    [
+        "git@github.com:iterative/scmrepo.git",
+        "ssh://login@server.com:12345/repository.git",
+    ],
+)
+def test_pygit2_ssh_error(tmp_dir: TmpDir, scm: Git, url):
+    backend = Pygit2Backend(tmp_dir)
+    with pytest.raises(NotImplementedError):
+        with backend.get_remote(url):
+            pass