在使用 Red Hat Satellite 时从 RHEL 7 到 RHEL 8 的 LEAPP 升级失败

Issue

• 当尝试从 RHEL 7.9 升级到 RHEL 8.x 时，我的客户端无法启用 RHEL 8 软件仓库并带有以下输出：

  Unable to install RHEL 8 userspace packages.
  'dnf', 'install', '-y', '--nogpgcheck', '--setopt=module_platform_id=platform:el8', '--setopt=keepcache=1', '--releasever', u'8.x', '--installroot', '/el8target', '--disablerepo', '*', '--enablerepo', u'rhel-8-for-x86_64-baseos-rpms', '--enablerepo', u'rhel-8-for-x86_64-appstream-rpms', u'rhel-8-for-x86_64-baseos-rpms', '--enablerepo', u'rhel-8-for-x86_64-appstream-rpms', '--enablerepo', u'rhel-8-for-x86_64-appstream-rpms', '--enablerepo', u'rhel-8-for-x86_64-baseos-rpms', 'dnf'] failed with exit code 1.",
  Failed to synchronize cache for repo 'rhel-8-for-x86_64-appstream-rpms', ignoring this repo.\n
  Failed to synchronize cache for repo 'rhel-8-for-x86_64-supplementary-rpms', ignoring this repo.\n
  Failed to synchronize cache for repo 'rhel-8-for-x86_64-baseos-rpms', ignoring this repo.\n
  Failed to synchronize cache for repo 'codeready-builder-for-rhel-8-x86_64-rpms', ignoring this repo.\n
  Error: Unable to find a match: dnf\n"}