loader.pypi.model: Log when encountering unexpected release scheme

Example:

['0.1.0.dev0', '0.1.0.dev1', '5.15.0', '5.15.0.dev0', '5.15.0.dev1',
'5.15.0.dev2', '5.15.0.dev3', '5.15.1', '5.15.2', '5.30.0', '5.30.1',
'5.30.2']

swh/loader/pypi/model.py

@@ -94,11 +94,16 @@ class PyPiProject:
         # sort releases in ascending order
         _releases = list(releases_dict.keys())
         __releases = []
-        for _release in _releases:
-            __releases.append([int(i) for i in _release.split('.')])
-        __releases.sort()
-        for rel in __releases:
-            yield '.'.join((str(i) for i in rel))
+        try:
+            for _release in _releases:
+                __releases.append([int(i) for i in _release.split('.')])
+            __releases.sort()
+            for rel in __releases:
+                yield '.'.join((str(i) for i in rel))
+        except Exception as e:
+            logging.error('Releases format: %s' % _releases)
+            logging.exception('Failing to sort release')
+            raise
 
     def releases(self):
         # The compute information per release