--- a/hgext3rd/evolve/obsdiscovery.py	Tue Aug 06 11:17:38 2019 +0200
+++ b/hgext3rd/evolve/obsdiscovery.py	Tue Aug 06 11:26:29 2019 +0200
@@ -353,7 +353,7 @@
         self._new.clear()
         if reset:
             self._valid = False
-        if '_con' in vars(self):
+        if r'_con' in vars(self):
             del self._con
 
     def get(self, rangeid):
@@ -377,7 +377,7 @@
             except (sqlite3.DatabaseError, sqlite3.OperationalError):
                 # something is wrong with the sqlite db
                 # Since this is a cache, we ignore it.
-                if '_con' in vars(self):
+                if r'_con' in vars(self):
                     del self._con
                 self._new.clear()
         return value
@@ -528,7 +528,7 @@
         repo = repo.unfiltered()
         try:
             with repo.lock():
-                if 'stablerange' in vars(repo):
+                if r'stablerange' in vars(repo):
                     repo.stablerange.save(repo)
                 self._save(repo)
         except error.LockError:
@@ -548,7 +548,7 @@
             #
             # operational error catch read-only and locked database
             # IntegrityError catch Unique constraint error that may arise
-            if '_con' in vars(self):
+            if r'_con' in vars(self):
                 del self._con
             self._new.clear()
             repo.ui.log('evoext-cache', 'error while saving new data: %s' % exc)
@@ -557,7 +557,7 @@
     def _trysave(self, repo):
         if self._con is None:
             util.unlinkpath(self._path, ignoremissing=True)
-            if '_con' in vars(self):
+            if r'_con' in vars(self):
                 del self._con
 
             con = self._db()
@@ -585,7 +585,7 @@
                 repo.ui.warn(msg)
                 self._new.clear()
                 self._valid = False
-                if '_con' in vars(self):
+                if r'_con' in vars(self):
                     del self._con
                 self._valid = False
                 return
@@ -618,7 +618,7 @@
     class obshashrepo(repo.__class__):
         @localrepo.unfilteredmethod
         def destroyed(self):
-            if 'obsstore' in vars(self):
+            if r'obsstore' in vars(self):
                 self.obsstore.rangeobshashcache.clear()
             toplevel = not util.safehasattr(self, '_destroying')
             if toplevel: