APT包索引文件位置查询及源索引错误导致安装失败的问题求助

Hey there, let's work through your issue with the broken package index and missing package version step by step!

一、APT本地包索引文件的具体位置 #

When you run sudo apt-get update, your system downloads package index files from all configured repositories and stores them locally in the /var/lib/apt/lists/ directory.

For your specific repo http://security.ubuntu.com/ubuntu jammy-security universe, the relevant index files will have names like:

• security.ubuntu.com_ubuntu_dists_jammy-security_universe_binary-amd64_Packages (uncompressed, human-readable version)
• security.ubuntu.com_ubuntu_dists_jammy-security_universe_binary-amd64_Packages.gz (compressed version that gets downloaded first, then unpacked)

These files hold all the metadata for packages in the repo—including version numbers, download URLs, and dependencies.

二、验证索引中的版本 mismatch 问题 #

To confirm that the index has an outdated or incorrect entry, you can search for the problematic package in the relevant index file with this command:

grep -A 10 -B 2 "python3-libxml2" /var/lib/apt/lists/security.ubuntu.com_ubuntu_dists_jammy-security_universe_binary-amd64_Packages

Look for the Version and Filename fields in the output. If it shows Version: 2.9.13+dfsg-1ubuntu0.2 and points to the missing .deb file, that confirms your local index is out of sync with what's actually hosted on the security repo.

三、临时解决办法（you already nailed this!） #

As you successfully tried manually, installing the newer available package first works around the broken index:

1. Grab the correct .deb file directly from the security repo's package directory
2. Install it with sudo dpkg -i libxml2_2.9.13+dfsg-1ubuntu0.3_amd64.deb
3. Then run sudo apt-get install yelp-tools again, which should now complete without errors

四、如何反馈这个问题（and further verification） #

First, make sure this isn't just a temporary sync issue with your local mirror:

• Try switching to a different official Ubuntu security mirror (update your /etc/apt/sources.list or files in /etc/apt/sources.list.d/ to use a regional mirror)
• Run sudo apt-get update again and attempt to install yelp-tools—if you still get the same error, it's likely a problem with the main security repo's index.

To report the issue to Ubuntu maintainers:

• Use the ubuntu-bug apt command in your terminal—it will walk you through submitting a bug report to Ubuntu's official bug tracker, automatically including key system details that help debug the problem.
• You can also manually submit a report: first search for existing reports about the jammy-security repo's libxml2 index mismatch. If none exist, create a new one with these details:
  • Your Ubuntu version (Jammy Jellyfish)
  • The exact error message you received
  • The version mismatch you found (index pointing to 0.2, repo hosting 0.3)
  • The steps you took to verify the issue

备注：内容来源于stack exchange，提问作者j0h