Fix Failed to fetch

Failed to fetch Hash Sum mismatch

Some index files failed to download, they have been ignored, or old ones used instead

• 方法一

  1.在Cydia内删除BigBoss源

  2.添加源，地址为
      此时应该能够顺利完成Download packages，并且此源内有内容
  3.在Cydia首页内“更多软件源”处继续添加Bigboss源，添加后这个BigBoss源内应该为空
  4.删除步骤2中添加的源，数据重新加载后，步骤2的源的内容应当原封不动出现在BigBoss源内，大功告成。

• 方法二 有效

  try going to the Changes tab and then tap Refresh. If you still get those errors, you might be behind a proxy or firewall that's blocking the files Cydia is trying to download.

• 方法三

  Add this repo:

  cydia.angelxwind.net
  And install iCleaner Pro.
  Then run iCleaner pro and clean your system and try Cydia after respringing.