官方说明我一直在尝试安装 PostgreSQL 12，但出现以下错误：No match for argument: postgresql12
Error: Unable to find a match: postgresql12
当我运行命令时，sudo dnf repolist这就是我得到的：
$ sudo dnf repolist
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Last metadata expiration check: 0:04:00 ago on Mon 24 Feb 2020 05:44:02 PM EST.
Modular dependency problems:
Problem 1: conflicting requests
- nothing provides module(perl:5.26) needed by module perl-DBD-SQLite:1.58:8010020190322125518:073fa5fe-0.x86_64
Problem 2: conflicting requests
- nothing provides module(perl:5.26) needed by module perl-DBI:1.641:8010020190322130042:16b3ab4d-0.x86_64
repo id repo name status
*epel Extra Packages for Enterprise Linux 8 - x86_64 4,885
*epel-modular Extra Packages for Enterprise Linux Modular 8 - x86_64 0
pgdg10 PostgreSQL 10 for RHEL/CentOS 8 - x86_64 793
pgdg11 PostgreSQL 11 for RHEL/CentOS 8 - x86_64 838
pgdg12 PostgreSQL 12 for RHEL/CentOS 8 - x86_64 635
pgdg94 PostgreSQL 9.4 for RHEL/CentOS 8 - x86_64 346
pgdg95 PostgreSQL 9.5 for RHEL/CentOS 8 - x86_64 516
pgdg96 PostgreSQL 9.6 for RHEL/CentOS 8 - x86_64 761
当我在sudo yum list postgresql12*这里运行命令时，我得到的是：
sudo yum list postgresql12*
Updating Subscription Management repositories.
This system is registered to Red Hat Subscription Management, but is not receiving updates. You can use subscription-manager to assign subscriptions.
Last metadata expiration check: 0:06:49 ago on Mon 24 Feb 2020 05:44:02 PM EST.
Modular dependency problems:
Problem 1: conflicting requests
- nothing provides module(perl:5.26) needed by module perl-DBD-SQLite:1.58:8010020190322125518:073fa5fe-0.x86_64
Problem 2: conflicting requests
- nothing provides module(perl:5.26) needed by module perl-DBI:1.641:8010020190322130042:16b3ab4d-0.x86_64
Available Packages
postgresql12-contrib-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-debugsource.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-devel.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-devel-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-libs.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-libs-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-llvmjit.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-llvmjit-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-odbc.x86_64 12.01.0000-1PGDG.rhel8 pgdg12
postgresql12-plperl-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-plpython.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-plpython-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-plpython3-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-pltcl-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-server-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
postgresql12-test-debuginfo.x86_64 12.2-2PGDG.rhel8 pgdg12
当我尝试禁用 postgresql 模块时没有任何反应：
sudo dnf -qy module disable postgresql
Error: Problems in request:
Modular dependency problems:
Problem 1: conflicting requests
- nothing provides module(perl:5.26) needed by module perl-DBD-SQLite:1.58:8010020190322125518:073fa5fe-0.x86_64
Problem 2: conflicting requests
- nothing provides module(perl:5.26) needed by module perl-DBI:1.641:8010020190322130042:16b3ab4d-0.x86_64