Software Update: This requires installing packages from unauthenticated sources

Question

When trying to install packages through the software updater on Ubuntu 14.04.1 LTS I get following error:

It's about these packages:

I have selected following settings from where to install updates from:

I have run following commands:

sudo apt-get clean
sudo apt-get update
sudo apt-get upgrade

sudo apt-get update gives following output:

Reading package lists... Done
W: GPG error: https://download.01.org trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A902DDA375E52366
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main i386 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-i386_Packages)

sudo apt-get upgrade gives following output:

The following packages have been kept back:
  libegl1-mesa libegl1-mesa-drivers libgbm1 libgl1-mesa-dri libgl1-mesa-glx
  libglapi-mesa libgles1-mesa libgles2-mesa libosmesa6 liboxideqt-qmlplugin
  liboxideqtcore0 libwayland-egl1-mesa libxatracker2 linux-generic
  linux-generic-pae linux-headers-generic linux-headers-generic-pae
  linux-image-generic linux-image-generic-pae oxideqt-codecs
  python-cupshelpers system-config-printer-gnome
0 upgraded, 0 newly installed, 0 to remove and 22 not upgraded.

---

UPDATE

With question How do I deal with "unauthenticated sources" errors in the Software Center?

issueing following commands:

sudo apt-get clean
cd /var/lib/apt
sudo mv lists lists.old
sudo mkdir -p lists/partial
sudo apt-get clean
sudo apt-get update

still gives following output:

Reading package lists... Done
W: GPG error: https://download.01.org trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A902DDA375E52366
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main i386 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-i386_Packages)

按照第二个答案：

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys A902DDA375E52366
sudo apt-get update

但收到以下错误：

W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main i386 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems

并且 apt-get update 不能解决问题

Answer 1

你可以运行：

sudo apt-get update && sudo apt-get dist-upgrade

Answer 2

要修复sources.list文件中的重复条目：

在具有 root/sudo 权限的编辑器中打开它，例如：

sudo nano /etc/apt/sources.list

并删除重复的行（无论哪一行）：

http://dl.google.com/linux/chrome/deb/

然后使用 ctrl-x 退出（y 保存）。像平常一样进行 apt-get 更新和升级。