Handle missing reflink dependency in the business logic

beets/util/__init__.py

@@ -13,6 +13,7 @@
 # included in all copies or substantial portions of the Software.
 
 """Miscellaneous utility functions."""
+
 from __future__ import annotations
 
 import errno
@@ -29,6 +30,7 @@ import traceback
 from collections import Counter
 from contextlib import suppress
 from enum import Enum
+from importlib import import_module
 from logging import Logger
 from multiprocessing.pool import ThreadPool
 from pathlib import Path
@@ -615,31 +617,33 @@ def reflink(
     Raise an `OSError` if `dest` already exists, unless `replace` is
     True. If `path` == `dest`, then do nothing.
 
-    If reflinking fails and `fallback` is enabled, try copying the file
-    instead. Otherwise, raise an error without trying a plain copy.
-
-    May raise an `ImportError` if the `reflink` module is not available.
+    If `fallback` is enabled, ignore errors and copy the file instead.
+    Otherwise, errors are re-raised as FilesystemError with an explanation.
     """
-    import reflink as pyreflink
-
     if samefile(path, dest):
         return
 
     if os.path.exists(syspath(dest)) and not replace:
         raise FilesystemError("file exists", "rename", (path, dest))
 
-    try:
-        pyreflink.reflink(path, dest)
-    except (NotImplementedError, pyreflink.ReflinkImpossibleError):
     if fallback:
-            copy(path, dest, replace)
-        else:
+        with suppress(Exception):
+            return import_module("reflink").reflink(path, dest)
+        return copy(path, dest, replace)
+
+    try:
+        import_module("reflink").reflink(path, dest)
+    except (ImportError, OSError):
+        raise
+    except Exception as exc:
+        msg = {
+            "EXDEV": "Cannot reflink across devices",
+            "EOPNOTSUPP": "Device does not support reflinks",
+        }.get(str(exc), "OS does not support reflinks")
+
         raise FilesystemError(
-                "OS/filesystem does not support reflinks.",
-                "link",
-                (path, dest),
-                traceback.format_exc(),
-            )
+            msg, "reflink", (path, dest), traceback.format_exc()
+        ) from exc
 
 
 def unique_path(path: bytes) -> bytes:

test/test_files.py

@@ -86,12 +86,10 @@ class MoveTest(BeetsTestCase):
         self.i.move(operation=MoveOperation.COPY)
         self.assertExists(self.path)
 
-    @NEEDS_REFLINK
     def test_reflink_arrives(self):
         self.i.move(operation=MoveOperation.REFLINK_AUTO)
         self.assertExists(self.dest)
 
-    @NEEDS_REFLINK
     def test_reflink_does_not_depart(self):
         self.i.move(operation=MoveOperation.REFLINK_AUTO)
         self.assertExists(self.path)
@@ -584,7 +582,6 @@ class SafeMoveCopyTest(BeetsTestCase):
         with pytest.raises(util.FilesystemError):
             util.copy(self.path, self.otherpath)
 
-    @NEEDS_REFLINK
     def test_unsuccessful_reflink(self):
         with pytest.raises(util.FilesystemError):
             util.reflink(self.path, self.otherpath)