Why does xargs cause apt-get to abort

First, you should understand why hash sum mismatch errors occur. In general, there are 2 reasons:

Firstly, Some apt repositories use LZMA (.xz) compressed metadata. apt before version 1.0 fails to decompressed LZMA archives correctly (sometimes) giving the hash sum mismatch error.

There's two work arounds for this:

1. Tell your apt client not to use XZ compressed metadata
2. Upgrade apt on your system to a version newer than 1.0

Check out this blog post I wrote about this issue which explains both work arounds in greater detail.

Secondly, APT repositories are inherently racy. The actual APT metadata is buggy and the design of it makes it impossible for apt clients to download the repository metadata in a consistent way if the apt-get update happens while the repository is being updated.

There's two work arounds for this:

1. Upgrade to a newer version of APT and ensure that the repository you create (or want to use) supports the Acquire-by-hash feature. This fixes the issue at its core, but not be possible in some cases if you don't control the repository.
2. You can delete the cached metadata on your system and try again. To do this, first run apt-get clean followed by rm -rf /var/lib/apt/lists/*. Next, run apt-get update. This will re-download all the metadata. If the repository you are trying to connect to doesn't update itself while you are running apt-get update, you will be fine. Otherwise, you'll have to do this again.

This sounds like it may work, but personally, I'd just use apt-offline.

From the manpage:

apt-offline brings offline package management functionality to Debian based system. It can be used to download packages and its dependencies to be installed later on (or required to update) a disconnected machine. Packages can be downloaded from a different connected machine.

Excerpt from Debian Administration:

Using apt-offline:

• You generate a signature on your Debian box at home and carry the signature file on a removable medium
• Now you take the USB Stick (with the apt-offline.txt signature file) to the office machine which could be running any linux version or even Windows.
• There, you could run apt-offline giving it the signature file.
• apt-offline would generate you an archive file or a folder with all the data. That data can be copied on a removable media. The removable media can be attached back to the disconnected Debian box at home and installed. (e.g. "apt-offline install /tmp/apt-offline.zip")