Git 1.7.4.2

Git for Ubuntu 10.04 has a major bug in that it keeps file descriptors open for every pack file. If you use git --mirror, you will easily run out of file descriptors. You may see the following error messages.

error: cannot create pipe for index-pack: Too many open files
fatal: fetch-pack: unable to fork off index-pack
error: cannot create pipe for pack-objects: Too many open files
fatal: git pack-objects failed: Too many open files
error: cannot create pipe for index-pack: Too many open files
fatal: fetch-pack: unable to fork off index-pack
error: cannot create pipe for pack-objects: Too many open files
fatal: git pack-objects failed: Too many open files

The fix was made in Git 1.7.4.2:
https://raw.github.com/gitster/git/master/Documentation/RelNotes/1.7.4.2.txt

 * We used to keep one file descriptor open for each and every packfile    that we have a mmap window on it (read: "in use"), even when for very    tiny packfiles.  We now close the file descriptor early when the entire    packfile fits inside one mmap window.

The fix is to add the repository to your /etc/apt/sources.list file at https://launchpad.net/~git-core/+archive/ppa:

https://launchpad.net/~git-core/+archive/ppa
deb http://ppa.launchpad.net/git-core/ppa/ubuntu lucid main
deb-src http://ppa.launchpad.net/git-core/ppa/ubuntu lucid main

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys E1DF1F24
sudo apt-get update
sudo apt-cache search git
sudo apt-get install git=1:1.7.9.4-1.1~ppa1~lucid1