使用更新命令yum时出现故障的解决方法

近日在运行系统更新命令yum update时候出现了如下错误提示：
Component: pirut
Summary: TBe8ae967a sqlitesack.py:94:_read_db_obj:TypeError: unsubscriptable object

Traceback (most recent call last):
File “/usr/sbin/pup”, line 407, in _apply
output = self.applyChanges(self.mainwin)
File “/usr/lib/python2.4/site-packages/pirut/__init__.py”, line 813, in applyChanges
self.checkDeps(mainwin)
File “/usr/lib/python2.4/site-packages/pirut/__init__.py”, line 550, in checkDeps
(result, msgs) = self.buildTransaction()
File “/usr/lib/python2.4/site-packages/yum/__init__.py”, line 647, in buildTransaction
(rescode, restring) = self.resolveDeps()
File “/usr/lib/python2.4/site-packages/yum/depsolve.py”, line 704, in resolveDeps
for po, dep in self._checkFileRequires():
File “/usr/lib/python2.4/site-packages/yum/depsolve.py”, line 939, in _checkFileRequires
if not self.tsInfo.getOldProvides(filename) and not self.tsInfo.getNewProvides(filename):
File “/usr/lib/python2.4/site-packages/yum/transactioninfo.py”, line 414, in getNewProvides
for pkg, hits in self.pkgSack.getProvides(name, flag, version).iteritems():
File “/usr/lib/python2.4/site-packages/yum/packageSack.py”, line 300, in getProvides
return self._computeAggregateDictResult(“getProvides”, name, flags, version)
File “/usr/lib/python2.4/site-packages/yum/packageSack.py”, line 470, in _computeAggregateDictResult
sackResult = apply(method, args)
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 861, in getProvides
return self._search(“provides”, name, flags, version)
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 43, in newFunc
return func(*args, **kwargs)
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 837, in _search
for pkg in self.searchFiles(name, strict=True):
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 43, in newFunc
return func(*args, **kwargs)
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 586, in searchFiles
self._sql_pkgKey2po(rep, cur, pkgs)
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 470, in _sql_pkgKey2po
pkg = self._packageByKey(repo, ob['pkgKey'])
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 413, in _packageByKey
po = self.pc(repo, cur.fetchone())
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 68, in __init__
self._read_db_obj(db_obj)
File “/usr/lib/python2.4/site-packages/yum/sqlitesack.py”, line 94, in _read_db_obj
setattr(self, item, _share_data(db_obj[item]))
TypeError: unsubscriptable object

Local variables in innermost frame:
item: name
db_obj: None

这个问题是由于yum的原数据损坏导致的，需要先删除原数据和数据库缓存，然后重建，问题即可解决
解决方法，依次运行以下命令：

yum clean metadata
yum clean dbcache
yum makecache