"data stream error" when cloning a git repository into a NFSv4 mounted directory with ACLs turned on

[Veit Kleeberger]

On an NFSv4 mounted directory with ACLs turned on, git refuses to clone a repository.
Cloning on local file systems works perfectly.

To reproduce the error use a NFSv4 mounted directory with enforced ACLs turned on (for example as provided by a NetApp Fileserver) and try to clone an existing repository, e.g.:
>> git clone git://gitorious.org/verisim/verisim.git

This will produce:
>> Cloning into verisim...
>> remote: Counting objects: 251, done.
>> remote: Compressing objects: 100% (247/247), done.
>> remote: Total 251 (delta 142), reused 0 (delta 0)
>> Receiving objects: 100% (251/251), 52.03 KiB, done.
>> error: inflate: data stream error (unknown compression method)
>> fatal: serious inflate inconsistency
>> fatal: index-pack failed

A strace or cloning to a local file system and copying the cloned repository to the NFS directory reveals the following:
It seems that git creates some readonly files and tries to write content into them.
(In the above example, e.g. verisim/.git/objects/pack/pack-4878e1ecd5a389fffd61b6b12b51ee61a8d19f39.idx)
As this violates access rights (you are not able to write to a readonly file if ACLs are correctly enforced) cloning the repository fails.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: git 1:1.7.4.1-3
ProcVersionSignature: Ubuntu 2.6.38-10.46-generic 2.6.38.7
Uname: Linux 2.6.38-10-generic x86_64
NonfreeKernelModules: openafs nvidia
Architecture: amd64
Date: Fri Aug 5 10:09:41 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 LANGUAGE=de_DE:en
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: git
UpgradeStatus: No upgrade log present (probably fresh install)