私はこの問題に固執しました： -
# apt-get install software-properties-common
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package software-properties-common
誰かがこの問題を解決する方法を教えてもらえますか？
これは apt-cache ポリシーの結果です。
apt-cache policy
Package files:
100 /var/lib/dpkg/status
release a=now
1000 http://downloads.mariadb.com/Tools/debian stretch/main amd64 Packages
release o=MariaDB Enterprise,n=stretch,l=MariaDB,c=main,b=amd64
origin downloads.mariadb.com
1000 http://downloads.mariadb.com/MaxScale/2.3/debian stretch/main amd64 Packages
release o=MariaDB,n=stretch,l=MariaDB Maxscale repository,c=main,b=amd64
origin downloads.mariadb.com
1000 http://downloads.mariadb.com/MariaDB/mariadb-10.3/repo/debian stretch/main amd64 Packages
release o=MariaDB,n=stretch,l=MariaDB,c=main,b=amd64
origin downloads.mariadb.com
500 http://mariadb.nethub.com.hk/repo/10.3/debian stretch/main ppc64el Packages
release o=MariaDB,n=stretch,l=MariaDB,c=main,b=ppc64el
origin mariadb.nethub.com.hk
500 http://mariadb.nethub.com.hk/repo/10.3/debian stretch/main i386 Packages
release o=MariaDB,n=stretch,l=MariaDB,c=main,b=i386
origin mariadb.nethub.com.hk
500 http://mariadb.nethub.com.hk/repo/10.3/debian stretch/main amd64 Packages
release o=MariaDB,n=stretch,l=MariaDB,c=main,b=amd64
origin mariadb.nethub.com.hk
500 http://security.debian.org/debian-security stretch/updates/main amd64 Packages
release v=9,o=Debian,a=stable,n=stretch,l=Debian-Security,c=main,b=amd64
origin security.debian.org
Pinned packages:
ベストアンサー1
/etc/apt/sources.listリポジトリ設定にはDebian 9リポジトリ（セキュアリポジトリを除く）は含まれていません。少なくとも含める必要があります。
deb http://deb.debian.org/debian stretch main
deb http://deb.debian.org/debian stretch-updates main
deb http://security.debian.org stretch/updates main