无法获取&一些索引文件无法下载

Question

在运行sudo apt-get update时，我将得到以下字符串错误：

Ign:1 http://dl.google.com/linux/chrome/deb stable InRelease                                     
Hit:2 http://ppa.launchpad.net/elementary-os/stable/ubuntu xenial InRelease                      
Ign:3 http://extras.ubuntu.com/ubuntu precise InRelease                                   
Hit:4 http://dl.google.com/linux/chrome/deb stable Release                                       
Ign:6 http://archive.canonical.com/ubuntu precise InRelease                                      
Hit:7 http://ppa.launchpad.net/n-muench/burg/ubuntu xenial InRelease                      
Ign:8 http://us.archive.ubuntu.com/ubuntu precise InRelease                                      
Get:9 http://extras.ubuntu.com/ubuntu precise Release [11,9 kB]                                  
Hit:10 http://archive.canonical.com/ubuntu precise Release                                       
Hit:11 http://ppa.launchpad.net/noobslab/macbuntu/ubuntu xenial InRelease                        
Get:13 http://us.archive.ubuntu.com/ubuntu precise-security InRelease [55,7 kB]                  
Hit:14 http://ppa.launchpad.net/elementary-os/os-patches/ubuntu xenial InRelease                 
Get:15 http://extras.ubuntu.com/ubuntu precise Release.gpg [72 B]                                
Ign:15 http://extras.ubuntu.com/ubuntu precise Release.gpg                                       
Hit:16 http://ppa.launchpad.net/philip.scott/elementary-tweaks/ubuntu xenial InRelease   
Ign:18 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial InRelease               
Hit:21 http://ppa.launchpad.net/videolan/stable-daily/ubuntu xenial InRelease                   
Get:22 http://us.archive.ubuntu.com/ubuntu precise-updates InRelease [55,7 kB]
Hit:17 http://extras.ubuntu.com/ubuntu precise/main Sources                                      
Ign:17 http://extras.ubuntu.com/ubuntu precise/main Sources                       
Hit:19 http://extras.ubuntu.com/ubuntu precise/main amd64 Packages                              
Ign:19 http://extras.ubuntu.com/ubuntu precise/main amd64 Packages  
Ign:23 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial Release
Hit:20 http://extras.ubuntu.com/ubuntu precise/main i386 Packages   
Ign:20 http://extras.ubuntu.com/ubuntu precise/main i386 Packages   
Hit:24 http://us.archive.ubuntu.com/ubuntu precise-backports InRelease
Ign:25 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 Packages    
Hit:17 http://extras.ubuntu.com/ubuntu precise/main Sources                                     
Ign:26 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main i386 Packages
Hit:27 http://us.archive.ubuntu.com/ubuntu precise Release          
Hit:19 http://extras.ubuntu.com/ubuntu precise/main amd64 Packages        
Ign:29 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main all Packages
Hit:20 http://extras.ubuntu.com/ubuntu precise/main i386 Packages
Ign:30 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en_US
Ign:31 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en     
Ign:32 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:33 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main DEP-11 64x64 Icons 
Ign:25 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 Packages     
Ign:26 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main i386 Packages      
Ign:29 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main all Packages       
Ign:30 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en_US  
Ign:31 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en     
Ign:32 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:33 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main DEP-11 64x64 Icons 
Ign:25 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 Packages     
Ign:26 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main i386 Packages      
Ign:29 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main all Packages       
Ign:30 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en_US  
Ign:31 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en     
Ign:32 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:33 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main DEP-11 64x64 Icons 
Ign:25 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 Packages     
Ign:26 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main i386 Packages      
Ign:29 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main all Packages       
Ign:30 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en_US  
Ign:31 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en     
Ign:32 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:33 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main DEP-11 64x64 Icons
Ign:25 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 Packages
Ign:26 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main i386 Packages
Ign:29 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main all Packages
Ign:30 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en_US
Ign:31 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en
Ign:32 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:33 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main DEP-11 64x64 Icons
Err:25 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 Packages
  404  Not Found
Ign:26 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main i386 Packages
Ign:29 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main all Packages
Ign:30 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en_US
Ign:31 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main Translation-en
Ign:32 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:33 http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial/main DEP-11 64x64 Icons
Fetched 123 kB in 35s (3.456 B/s)
Reading package lists... Done
W: http://archive.canonical.com/ubuntu/dists/precise/Release.gpg: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: GPG error: http://extras.ubuntu.com/ubuntu precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 16126D3A3E5C1192
W: The repository 'http://extras.ubuntu.com/ubuntu precise Release' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: http://us.archive.ubuntu.com/ubuntu/dists/precise-security/InRelease: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: http://us.archive.ubuntu.com/ubuntu/dists/precise-updates/InRelease: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: The repository 'http://ppa.launchpad.net/versable/elementary-update/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: http://us.archive.ubuntu.com/ubuntu/dists/precise-backports/InRelease: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: http://us.archive.ubuntu.com/ubuntu/dists/precise/Release.gpg: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
E: Failed to fetch http://ppa.launchpad.net/versable/elementary-update/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.

这些错误意味着什么，我如何修正它们？

我的sources.list文件内容是

#############################################################
################### OFFICIAL UBUNTU REPOS ###################
#############################################################

###### Ubuntu Main Repos
deb http://us.archive.ubuntu.com/ubuntu/ main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted universe multiverse

###### Ubuntu Update Repos
deb http://us.archive.ubuntu.com/ubuntu/ precise-security main restricted universe multiverse
deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted universe multiverse
deb http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-security main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse

###### Ubuntu Partner Repo
deb http://archive.canonical.com/ubuntu precise partner
deb-src http://archive.canonical.com/ubuntu precise partner

###### Ubuntu Extras Repo
deb http://extras.ubuntu.com/ubuntu precise main
deb-src http://extras.ubuntu.com/ubuntu precise main

Answer 1

从您的apt-get update输出中可以看出，您有Xenial中的precise存储库，这是问题的根源。您应该从sources.list文件中删除这些行。

1. 首先，在终端sudo -i gedit /etc/apt/sudo.列表中使用此命令打开文件
2. 然后删除包含precise的所有行。
3. 然后保存文件并退出gedit。现在做sudo apt-get update。

问题应该解决了。