Log the version of jsondiff we are using.

diffoscope/comparators/json.py

@@ -19,6 +19,7 @@
 
 import re
 import json
+import logging
 import collections
 
 from diffoscope.difference import Difference
@@ -26,6 +27,8 @@ from diffoscope.tools import python_module_missing
 
 from .utils.file import File
 
+logger = logging.getLogger(__name__)
+
 try:
     import jsondiff
 except ImportError:  # noqa
@@ -74,6 +77,8 @@ class JSONFile(File):
         if jsondiff is None:
             return
 
+        logger.debug(f"Comparing using jsondiff {jsondiff.__version__}")
+
         a = getattr(self, "parsed", {})
         b = getattr(other, "parsed", {})