Add／Remove Software的问题？？？

fede

我使用的是FC5，当我点击开始菜单中的Add／Remove Software时（当然要输入根密码），会出现exception occurred。具体内容如下：

Component: Software Manager
Summary: TB4426d5a1 ConfigParser.py:490:_readarsingError: File contains parsing errors: ///etc/yum.repos.d/fedora-devel.repo
        [line  4]: 'nt/$basearch/\n'

Traceback (most recent call last):
  File "/usr/sbin/pirut", line 363, in ?
    main()
  File "/usr/sbin/pirut", line 358, in main
    pm = PackageManager()
  File "/usr/sbin/pirut", line 56, in __init__
    GraphicalYumBase.__init__(self, False)
  File "/usr/lib/python2.4/site-packages/pirut/__init__.py", line 122, in __init__
    self.doConfigSetup()
  File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 104, in doConfigSetup
    self.getReposFromConfig()
  File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 135, in getReposFromConfig
    parser.read(files)
  File "/usr/lib/python2.4/site-packages/yum/parser.py", line 225, in read
    IncludingConfigParser.read(self,filename)
  File "/usr/lib/python2.4/site-packages/yum/parser.py", line 126, in read
    ConfigParser.read(self,filename)
  File "/usr/lib/python2.4/ConfigParser.py", line 267, in read
    self._read(fp, filename)
  File "/usr/lib/python2.4/ConfigParser.py", line 490, in _read
    raise e
ParsingError: File contains parsing errors: ///etc/yum.repos.d/fedora-devel.repo
        [line  4]: 'nt/$basearch/\n'

Local variables in innermost frame:
sectname: development
cursect: {'gpgcheck': '0', '__name__': 'development', 'mirrorlist': 'http://fedora.redhat.com/download/mirrors/fedora-core-rawhide', 'enabled': '1', 'name': 'Fedora Core $releasever - Development Tree'}
e: File contains parsing errors: ///etc/yum.repos.d/fedora-devel.repo
        [line  4]: 'nt/$basearch/\n'
fpname: ///etc/yum.repos.d/fedora-devel.repo
vi: =
mo: <_sre.SRE_Match object at 0x41c8ef70>
optname: gpgcheck
fp: <open file '///etc/yum.repos.d/fedora-devel.repo', mode 'r' at 0x41c88f98>
lineno: 7
line:
self: <yum.parser.IncludedDirConfigParser instance at 0x41ca538c>
optval: 0

请问是怎么回事？偶是一名linux新手。