aptからhttpsのURLにアクセスする際、以下のようなエラーが出る場合がある。 # apt update Hit:1 http://archive.ubuntu.com/ubuntu xenial InRelease Hit:2 http://security.ubuntu.com/ubuntu xenial-security InRelease Hit:3 http://archive.ubuntu.com/ubuntu xenial-updates InRelease Hit:4 http://archive.ubuntu.com/ubuntu xenial-backports InRelease Reading package lists... Done E: The method driver /usr/lib/apt/methods/https could not be found. N: Is the package apt-transport-https installed? E: Failed to fetch https://dl.winehq.org/wine-builds/ubuntu/dists/xenial/InRelease E: Some index files failed to download. They have been ignored, or old ones used instead. apt-transport-httpsをインストールすることで解決する # apt install apt-transport-https