最小化安装Centos7，配置了阿里云官方yum源之后，使用yum源报错

问题：最小化安装Centos7，配置了阿里云官方yum源之后，一直无法使用yum

Error: Depsolving loop limit reached.
Error: Package: rpm-python-4.11.3-45.el7.x86_64 (@anaconda)
           Requires: librpm.so.3()(64bit)
           Removing: rpm-libs-4.11.3-45.el7.x86_64 (@anaconda)
               librpm.so.3()(64bit)
           Updated By: rpm-libs-4.14.3-19.el8.x86_64 (base)
              ~librpm.so.8()(64bit)
Error: Package: rpm-python-4.11.3-45.el7.x86_64 (@anaconda)
           Requires: librpmsign.so.1()(64bit)
           Removing: rpm-build-libs-4.11.3-45.el7.x86_64 (@anaconda)
               librpmsign.so.1()(64bit)
           Updated By: rpm-build-libs-4.14.3-19.el8.x86_64 (base)
              ~librpmsign.so.8()(64bit)
Error: Package: libidn2-2.3.4-1.el7.x86_64 (epel)
           Requires: libunistring.so.0()(64bit)
           Removing: libunistring-0.9.3-9.el7.x86_64 (@anaconda)
               libunistring.so.0()(64bit)
           Updated By: libunistring-0.9.9-3.el8.x86_64 (base)
              ~libunistring.so.2()(64bit)
Error: Package: rpm-python-4.11.3-45.el7.x86_64 (@anaconda)
           Requires: librpmbuild.so.3()(64bit)
           Removing: rpm-build-libs-4.11.3-45.el7.x86_64 (@anaconda)
               librpmbuild.so.3()(64bit)
           Updated By: rpm-build-libs-4.14.3-19.el8.x86_64 (base)
              ~librpmbuild.so.8()(64bit)
Error: Package: rpm-python-4.11.3-45.el7.x86_64 (@anaconda)
           Requires: rpm = 4.11.3-45.el7
           Removing: rpm-4.11.3-45.el7.x86_64 (@anaconda)
               rpm = 4.11.3-45.el7
           Updated By: rpm-4.14.3-19.el8.x86_64 (base)
               rpm = 4.14.3-19.el8
Error: Package: rpm-python-4.11.3-45.el7.x86_64 (@anaconda)
           Requires: liblua-5.1.so()(64bit)
           Removing: lua-5.1.4-15.el7.x86_64 (@anaconda)
               liblua-5.1.so()(64bit)
           Updated By: lua-5.3.4-12.el8.x86_64 (AppStream)
               Not found
Error: Package: systemd-sysv-219-78.el7.x86_64 (@anaconda)
           Requires: systemd = 219-78.el7
           Removing: systemd-219-78.el7.x86_64 (@anaconda)
               systemd = 219-78.el7
           Obsoleted By: systemd-239-51.el8_5.2.x86_64 (base)
               systemd = 239-51.el8_5.2
           Updated By: systemd-239-51.el8_5.2.x86_64 (base)
               systemd = 239-51.el8_5.2
           Available: systemd-239-51.el8.i686 (base)
               systemd = 239-51.el8
Error: Package: rpm-python-4.11.3-45.el7.x86_64 (@anaconda)
           Requires: librpmio.so.3()(64bit)
           Removing: rpm-libs-4.11.3-45.el7.x86_64 (@anaconda)
               librpmio.so.3()(64bit)
           Updated By: rpm-libs-4.14.3-19.el8.x86_64 (base)
              ~librpmio.so.8()(64bit)
Error: Package: python-libs-2.7.5-89.el7.x86_64 (@anaconda)
           Requires: libreadline.so.6()(64bit)
           Removing: readline-6.2-11.el7.x86_64 (@anaconda)
               libreadline.so.6()(64bit)
           Updated By: readline-7.0-10.el8.x86_64 (base)
              ~libreadline.so.7()(64bit)
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

解决办法：还是使用之前的yum配置文件，

清除缓存：yum clean all

生成新的缓存：yum makecache

升级软件包：yum  update

之后就可以使用yum了