153         self.cachevfs = vfsclass(self.vfs.join('cache'))

   153         self.cachevfs = vfsclass(self.vfs.join('cache'))

   154         self._phasedefaults = []

   154         self._phasedefaults = []

   155 

   155 

   156         self.names = namespaces.namespaces()

   156         self.names = namespaces.namespaces()

   157         self.filtername = None

   157         self.filtername = None

   158 

   159 

   159         try:

   160         try:

   160             requirements = set(self.vfs.read(b'requires').splitlines())

   161             requirements = set(self.vfs.read(b'requires').splitlines())

   161         except IOError as inst:

   162         except IOError as inst:

   162             if inst.errno != errno.ENOENT:

   163             if inst.errno != errno.ENOENT: