亲测有效：虚拟机安装gcc，报错Could not retrieve mirrorlist http://mirrorlist.centos.org
（网卡配置资料）
原因：
网络问题
报错详情：
One of the configured repositories failed (未知),and yum doesn't have enough cached data to continue. At this point the onlysafe thing yum can do is fail. There are a few ways to work "fix" this:1. Contact the upstream for the repository and get them to fix the problem.2. Reconfigure the baseurl/etc. for the repository, to point to a workingupstream. This is most often useful if you are using a newerdistribution release than is supported by the repository (and thepackages for the previous distribution release still work).3. Run the command with the repository temporarily disabledyum --disablerepo=<repoid> ...4. Disable the repository permanently, so yum won't use it by default. Yumwill then just ignore the repository until you permanently enable itagain or use --enablerepo for temporary usage:yum-config-manager --disable <repoid>orsubscription-manager repos --disable=<repoid>5. Configure the failing repository to be skipped, if it is unavailable.Note that yum will try to contact the repo. when it runs most commands,so will have to try and fail each time (and thus. yum will be be muchslower). If it is a very temporary problem though, this is often a nicecompromise:yum-config-manager --save --setopt=<repoid>.skip_if_unavailable=trueCannot find a valid baseurl for repo: base/7/x86_64
解决步骤：
1、修改虚拟机的网络连接模式为 NAT模式
2、右击桌面，打开终端
①首先查看网关配置文件名：
输入
ifconfig
②配置网卡信息：
vi /etc/sysconfig/network-scripts/ifcfg-ens32
两种方法：
点击键盘 I ，开始输入
第一种：自动配置
①
1、BOOTPROTO=dhcp（自动获取ip）
2、ONBOOT=yes（设置开机自启动）
②
ESC--》:wq
在终端输入
service network restart
重启网络服务
ping www.baidu.com
查看网络是否通，如图
第二种：手动配置（之前配置有用的，但重新做了一遍，又不行了。把大体思路记录下吧）
①主机cmd,输入：
ipconfig
找到所用的网的IP
BOOTPROTO= static (需手动配置）
②
ESC--》:wq
在终端输入
service network restart
重启网络服务
ping www.baidu.com
查看网络是否通，如图
验证
安装gcc
yum -y install gcc gcc-c++ autoconf pcre pcre-devel make automake
yum -y install wget httpd-tools vim
查看 gcc版本
gcc -v
输出以上信息，即为成功