来源：https://unix.stackexchange.com/questions/198000/bypass-gpg-signature-checks-only-for-a-single-repository/198454#198454
在 sources.list 里面出问题的 deb 后面加一个选项 [trusted=yes]
类似这个
deb [trusted=yes] http://localmachine/debian wheezy main
或者
deb [ allow-insecure=yes ] ...