每次我尝试执行软件更新时，我都会从软件管理器收到此错误：
W:GPG error: http://download.virtualbox.org/virtualbox/debian xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A2F683C52980AECF, W:The repository 'http://download.virtualbox.org/virtualbox/debian xenial InRelease' is not signed., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., W:There is no public key available for the following key IDs:
A2F683C52980AECF , W:The repository 'http://ppa.launchpad.net/blackmage/f.lux/ubuntu xenial Release' does not have a Release file., W:Data from …我正在尝试将我的 OpenGL 驱动程序更新到最新版本。我尝试了以下ppas：
ppa:oibaf/graphics-drivers
ppa:eek:ibaf/graphics-drivers
ppa:ubuntu-x-swat/updates
到目前为止没有任何效果。有什么解决办法吗？
glxinfo 的输出 | 格雷普 OpenGL
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) HD Graphics 405 (Braswell)
OpenGL core profile version string: 4.5 (Core Profile) Mesa 17.2.0-devel - padoka PPA
OpenGL core profile shading language version string: 4.50
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 3.0 Mesa 17.2.0-devel - padoka PPA
OpenGL shading language …