Evgeniy Polyakov [off-list ref] writes:
$ git clone http://kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Getting alternates list for http://kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git/
Getting pack list for http://kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git/
Getting index for pack 81cec7c6b26c755e466a79de8dbe1c7b827a48d6
error: non-monotonic index
/usr/bin/git-clone: line 33: 2025 Segmentation fault git-http-fetch -v -a -w "$tname" "$name" "$1/"
$ git --version
git version 1.4.4.4
The repository you are cloning uses pack idx version #2; 1.4.4.4 predates it
by a wide margin.