CentOS8 解决 yum元数据下载失败的方法

模块依赖问题 问题 1: conflicting requests

• nothing provides module(perl:5.26) needed by module perl-DBD-MySQL:4.046:8010020191114030811:073fa5fe-0.x86_64
  问题 2: conflicting requests
  
• nothing provides module(perl:5.26) needed by module perl-DBD-SQLite:1.58:8010020191114033549:073fa5fe-0.x86_64
  问题 3: conflicting requests
  
• nothing provides module(perl:5.26) needed by module perl-DBI:1.641:8010020191113222731:16b3ab4d-0.x86_64
  元数据缓存已建立。