hg: Log original exception when doing the merge with rebase.

rhodecode/lib/vcs/backends/hg/repository.py

@@ -607,6 +607,10 b' class MercurialRepository(BaseRepository'
                 self._update(bookmark_name)
                 return self._identify(), True
             except RepositoryError:
+                # The rebase-abort may raise another exception which 'hides'
+                # the original one, therefore we log it here.
+                log.exception('Error while rebasing shadow repo during merge.')
+
                 # Cleanup any rebase leftovers
                 self._remote.rebase(abort=True)
                 self._remote.update(clean=True)
@@ -715,8 +719,8 b' class MercurialRepository(BaseRepository'
                     merge_succeeded = True
                 except RepositoryError:
                     log.exception(
-                        'Failure when doing local from the shadow repository '
-                        'to the target repository.')
+                        'Failure when doing local push from the shadow '
+                        'repository to the target repository.')
                     merge_succeeded = False
                     merge_failure_reason = MergeFailureReason.PUSH_FAILED
             else:

rhodecode/model/db.py

@@ -2794,7 +2794,9 b' class CacheKey(Base, BaseModel):'
 
             Session().commit()
         except Exception:
-            log.error(traceback.format_exc())
+            log.exception(
+                'Cache key invalidation failed for repository %s',
+                safe_str(repo_name))
             Session().rollback()
 
     @classmethod