[MRG] fix(write.py): throw warning instead of error on conflicting bids versions

mne_bids/tests/test_write.py

@@ -414,7 +414,7 @@ def test_make_dataset_description(tmp_path, monkeypatch):
         make_dataset_description(path=tmp_path, name="tst", source_datasets=s_ds)
 
     monkeypatch.setattr(write, "BIDS_VERSION", "old")
-    with pytest.raises(ValueError, match="Previous BIDS version used"):
+    with pytest.warns(UserWarning, match="Conflicting BIDSVersion found*"):
         make_dataset_description(path=tmp_path, name="tst")
 
 

mne_bids/write.py

@@ -17,6 +17,7 @@
 from datetime import datetime, timezone, timedelta
 import shutil
 from collections import defaultdict, OrderedDict
+import warnings
 
 from pkg_resources import parse_version
 
@@ -1324,11 +1325,13 @@ def make_dataset_description(
         with open(fname, "r", encoding="utf-8-sig") as fin:
             orig_cols = json.load(fin)
         if "BIDSVersion" in orig_cols and orig_cols["BIDSVersion"] != BIDS_VERSION:
-            raise ValueError(
-                "Previous BIDS version used, please redo the "
-                "conversion to BIDS in a new directory "
-                "after ensuring all software is updated"
+            warnings.warn(
+                "Conflicting BIDSVersion found in dataset_description.json! "
+                "Consider setting BIDS root to a new directory and redo "
+                "conversion after ensuring all software has been updated. "
+                "Original dataset description will not be overwritten."
             )
+            overwrite = False
         for key in description:
             if description[key] is None or not overwrite:
                 description[key] = orig_cols.get(key, None)