config: wrap UnicodeDecodeErrors on load

dvc/config.py

@@ -176,7 +176,10 @@ class Config(dict):
 
         if fs.exists(filename):
             with fs.open(filename) as fobj:
-                conf_obj = ConfigObj(fobj)
+                try:
+                    conf_obj = ConfigObj(fobj)
+                except UnicodeDecodeError as exc:
+                    raise ConfigError(str(exc)) from exc
         else:
             conf_obj = ConfigObj()
         return _parse_named(_lower_keys(conf_obj.dict()))

tests/unit/test_config.py

@@ -3,7 +3,7 @@ import textwrap
 
 import pytest
 
-from dvc.config import Config
+from dvc.config import Config, ConfigError
 from dvc.fs import LocalFileSystem
 
 
@@ -70,3 +70,14 @@ def test_s3_ssl_verify(tmp_dir, dvc):
             ssl_verify = /path/to/custom/cabundle.pem
         """
     )
+
+
+def test_load_unicode_error(tmp_dir, dvc, mocker):
+    config = Config(validate=False)
+    mocker.patch(
+        "configobj.ConfigObj",
+        side_effect=UnicodeDecodeError("", b"", 0, 0, ""),
+    )
+    with pytest.raises(ConfigError):
+        with config.edit():
+            pass