centos8 制作repodata报错 No available modular metadata for modular package

最近使用了centos8，但是制作repodata的时候总是报 Error: No available modular metadata for modular package 错误，搜索了一下终于可以解决了

安装modular metadata生成工具

dnf install python3-devel python3 gcc
dnf install python3-createrepo_c
dnf install python3-libdnf 
dnf install python3-libmodulemd
yum install  http://mirrors.aliyun/centos/8.2.2004/BaseOS/x86_64/os/Packages/libmodulemd-2.8.2-1.el8.x86_64.rpm

# dnf install modulemd-tools

git clone https://github/rpm-software-management/modulemd-tools.git
cd modulemd-tools/repo2module/
python3 setup.py install --user

创建repodata 和 modular metadata

cd /root/pkgs/mariadb
createrepo_c .
/root/.local/bin/repo2module  -s stable -d . modules.yaml
modifyrepo_c --mdtype=modules modules.yaml repodata/