掌機 - FC3000 - 解決Release signed by unknown key (key id 40976EAF437D05B5)問題

參考資訊：
https://github.com/ValveSoftware/steam-runtime/issues/81

問題如下：

$ sudo debootstrap --arch armel --foreign precise precise https://old-releases.ubuntu.com/ubuntu/
    I: Retrieving InRelease
    I: Retrieving Release
    I: Retrieving Release.gpg
    I: Checking Release signature
    E: Release signed by unknown key (key id 40976EAF437D05B5)
       The specified keyring /usr/share/keyrings/ubuntu-archive-keyring.gpg may be incorrect or out of date.
       You can find the latest Debian release key at https://ftp-master.debian.org/keys.html

解法如下(加上--no-check-gpg)：

$ sudo debootstrap --arch armel --no-check-gpg --foreign precise precise https://old-releases.ubuntu.com/ubuntu/