源CentOS7.6 目标BC-Linux-OpenEuler21.10的版本，提示如下报错
安装 x2openEuler 客户端包失败，出现错误为：failed to install x2openEuler-upgrade, result is Repository extras is listed more than once in the configuration
错误：软件包：python-libs-2.7.5-94.el7_9.x86_64 (updates)
需要：libgdbm.so.4()(64bit)
正在删除: gdbm-1.10-8.el7.x86_64 (@anaconda)
libgdbm.so.4()(64bit)
更新，由: 1:gdbm-1.18.1-2.oe1.x86_64 (update)
~libgdbm.so.6()(64bit)
错误：软件包：4:perl-macros-5.16.3-299.el7_9.x86_64 (updates)
需要：perl(:MODULE_COMPAT_5.16.3)
正在删除: 4:perl-5.16.3-293.el7.x86_64 (@anaconda)
perl(:MODULE_COMPAT_5.16.3)
更新，由: 4:perl-5.28.3-6.oe1.x86_64 (baseos)
未找到
可用: 4:perl-5.16.3-297.el7.x86_64 (base)
perl(:MODULE_COMPAT_5.16.3)
可用: 4:perl-5.16.3-299.el7_9.x86_64 (updates)
perl(:MODULE_COMPAT_5.16.3)
错误：软件包：python-2.7.5-94.el7_9.x86_64 (updates)
需要：python-libs(x86-64) = 2.7.5-94.el7_9
正在删除: python-libs-2.7.5-76.el7.x86_64 (@anaconda)
python-libs(x86-64) = 2.7.5-76.el7
更新，由: python-libs-2.7.5-94.el7_9.x86_64 (updates)
python-libs(x86-64) = 2.7.5-94.el7_9
取代，由: python2-2.7.18-1.oe1.x86_64 (baseos)
python-libs(x86-64) = 2.7.18-1.oe1
可用: python-libs-2.7.5-89.el7.x86_64 (base)
python-libs(x86-64) = 2.7.5-89.el7
可用: python-libs-2.7.5-90.el7.x86_64 (updates)
python-libs(x86-64) = 2.7.5-90.el7
可用: python-libs-2.7.5-92.el7_9.x86_64 (updates)
python-libs(x86-64) = 2.7.5-92.el7_9
可用: python-libs-2.7.5-93.el7_9.x86_64 (updates)
python-libs(x86-64) = 2.7.5-93.el7_9
错误：软件包：systemd-sysv-219-78.el7_9.9.x86_64 (updates)
需要：systemd = 219-78.el7_9.9
正在删除: systemd-219-62.el7.x86_64 (@anaconda)
systemd = 219-62.el7
取代，由: systemd-243-51.oe1.x86_64 (update)
systemd = 243-51.oe1
更新，由: systemd-243-51.oe1.x86_64 (update)
systemd = 243-51.oe1
可用: systemd-219-78.el7.x86_64 (base)
systemd = 219-78.el7
可用: systemd-219-78.el7_9.2.x86_64 (updates)
systemd = 219-78.el7_9.2
可用: systemd-219-78.el7_9.3.x86_64 (updates)
systemd = 219-78.el7_9.3
可用: systemd-219-78.el7_9.5.x86_64 (updates)
systemd = 219-78.el7_9.5
可用: systemd-219-78.el7_9.7.x86_64 (updates)
systemd = 219-78.el7_9.7
可用: systemd-219-78.el7_9.9.x86_64 (updates)
systemd = 219-78.el7_9.9
可用: systemd-243-38.oe1.x86_64 (baseos)
systemd = 243-38.oe1
可用: systemd-243-39.oe1.x86_64 (update)
systemd = 243-39.oe1
可用: systemd-243-45.oe1.x86_64 (update)
systemd = 243-45.oe1
可用: systemd-243-46.oe1.x86_64 (update)
systemd = 243-46.oe1
可用: systemd-243-50.oe1.x86_64 (update)
systemd = 243-50.oe1
但是我在源CentOS7.9 目标BC-Linux-OpenEuler21.10的版本可正常升级，
我参考了这个案例中的YUM源 x2openEuler升级CentOS 7.5到openEuler22.03-SP4升级前检查报错 - Migration 迁移 - openEuler 论坛
这是什么原因？是我的CentOS7.6的机器上的YUM源有问题吗？
有CentOS7.6的YUM源吗？哪位大神可分享一下吗 谢谢