repository: clear error for borg 1.x repositories, fixes crash w/o --from-borg1

docs/installation.rst

@@ -188,11 +188,11 @@ development header files (sometimes in a separate `-dev` or `-devel` package).
   - Additionally, your OS will need to have FUSE support installed
     (e.g. a package `fuse` for fuse 2 or a package `fuse3` for fuse 3 support).
 * Optionally, if you wish to use S3/B2 Backend:
-  - borgstore[rest,blake3,s3] ~= 0.6.1 (use `pip install borgbackup[s3]`)
+  - borgstore[rest,blake3,s3] ~= 0.6.4 (use `pip install borgbackup[s3]`)
 * Optionally, if you wish to use SFTP Backend:
-  - borgstore[rest,blake3,sftp] ~= 0.6.1 (use `pip install borgbackup[sftp]`)
+  - borgstore[rest,blake3,sftp] ~= 0.6.4 (use `pip install borgbackup[sftp]`)
 * Optionally, if you wish to use rclone Backend:
-  - borgstore[rest,blake3,rclone] ~= 0.6.1 (use `pip install borgbackup[rclone]`)
+  - borgstore[rest,blake3,rclone] ~= 0.6.4 (use `pip install borgbackup[rclone]`)
 * Optionally, if you wish to use the TUI (``borg --cockpit``):
   - textual >= 6.8.0 (use `pip install borgbackup[cockpit]`)
 

docs/internals/frontends.rst

@@ -861,6 +861,8 @@ Errors
         Repository permission denied: {}
     Repository.KeyRequired rc: 28 traceback: yes
         Repository {} needs its key to access the store object {}, but no key was set.
+    Repository.LegacyRepository rc: 29 traceback: no
+        {} looks like a borg 1.x repository, use --from-borg1 to access it (e.g. with borg transfer).
 
     MandatoryFeatureUnsupported rc: 25 traceback: no
         Unsupported repository feature(s) {}. A newer version of Borg is required to access this repository.

pyproject.toml

@@ -31,7 +31,7 @@ license = "BSD-3-Clause"
 license-files = ["LICENSE", "AUTHORS"]
 dependencies = [
   "borghash ~= 0.2.0",
-  "borgstore[rest,blake3] ~= 0.6.1",
+  "borgstore[rest,blake3] ~= 0.6.4",
   "msgpack >=1.0.3, <=1.2.2",
   "packaging",
   "platformdirs >=3.0.0, <5.0.0; sys_platform == 'darwin'",  # for macOS: breaking changes in 3.0.0.
@@ -57,9 +57,9 @@ mfusepy = ["mfusepy >= 3.1.0, <4.0.0"]  # fuse 2+3, high-level
 # a pypi release of borgbackup can't contain a dependency on github!
 # mfusepym = ["mfusepy @ git+https://github.com/mxmlnkn/mfusepy.git@master"]
 nofuse = []
-s3 = ["borgstore[rest,blake3,s3] ~= 0.6.1"]
-sftp = ["borgstore[rest,blake3,sftp] ~= 0.6.1"]
-rclone = ["borgstore[rest,blake3,rclone] ~= 0.6.1"]
+s3 = ["borgstore[rest,blake3,s3] ~= 0.6.4"]
+sftp = ["borgstore[rest,blake3,sftp] ~= 0.6.4"]
+rclone = ["borgstore[rest,blake3,rclone] ~= 0.6.4"]
 cockpit = ["textual>=6.8.0"]  # might also work with older versions, untested
 
 [project.urls]

src/borg/repository.py

@@ -886,6 +886,11 @@ class KeyRequired(ErrorWithTraceback):
 
         exit_mcode = 28
 
+    class LegacyRepository(Error):
+        """{} looks like a borg 1.x repository, use --from-borg1 to access it (e.g. with borg transfer)."""
+
+        exit_mcode = 29
+
     # Whole packs kept in memory for reads; the least recently used is evicted first.
     # Memory use is this count times the pack size.
     PACK_READER_CACHE_SIZE = 3
@@ -1141,6 +1146,8 @@ def _load_config(self):
             # only shows up here, when the first request fails with BackendDoesNotExist (#10365).
             raise self.DoesNotExist(str(self._location)) from None
         except StoreObjectNotFound:
+            if self._is_legacy_repository():
+                raise self.LegacyRepository(str(self._location)) from None
             # the store exists, but has no repository config: a repository that lost its config, something
             # that never was a borg 2 repository, or the leftover of an interrupted repo-create (see create()).
             raise _ConfigMissing() from None
@@ -1159,6 +1166,19 @@ def _load_config(self):
             # the crypto suite is recorded by both entries or by none, see save_config().
             raise self.InvalidRepository(str(self._location))
 
+    def _is_legacy_repository(self):
+        """Does the (opened) store look like a borg 1.x repository?
+
+        A borg 1.x repository has a config *file* where borg 2 has the config/ namespace, so the store
+        object config/config is not found. The backend (not the Store, which only knows names within
+        namespaces) can look at that file-or-namespace directly.
+        """
+        try:
+            info = self.store.backend.info("config")
+        except (StoreBackendError, OSError):  # e.g. PermissionDenied, connection errors
+            return False
+        return info.exists and not info.directory
+
     def looks_like_borg_store(self):
         """Does the (opened, config-less) store have the packs, archives, index and config namespaces?
 

src/borg/testsuite/repository_test.py

@@ -116,6 +116,19 @@ def failing_rest_backend(location):
     assert "unrecognized arguments: --rest" in str(exc_info.value)
 
 
+@pytest.mark.parametrize("proto", ["file", "ssh"])
+def test_open_legacy_repository(tmp_path, proto):
+    # A borg 1.x repository (config is a file, not the config/ namespace) raises Repository.LegacyRepository.
+    path = tmp_path / "v1repo"
+    (path / "data").mkdir(parents=True)
+    (path / "config").write_text("[repository]\nversion = 1\nsegments_per_dir = 1000\nid = 00\n")
+    (path / "README").write_text("This is a Borg Backup repository.\n")
+    location = Location(os.fspath(path) if proto == "file" else f"ssh://__testsuite__/{os.fspath(path)}")
+    with pytest.raises(Repository.LegacyRepository):
+        with Repository(location, exclusive=True):
+            pass
+
+
 @pytest.fixture()
 def repository(tmp_path):
     repository_location = os.fspath(tmp_path / "repository")