git-clone-fail-demo

The scripts in this directory demonstrates a problem with git: "git
clone" may fail if somebody pushes changes to the repository while you
are cloning it.  This is true for at least repositories accessed via
ssh and and local repositories.  I've tested local access with Git
1.6.0, 1.7.9 and 1.7.10.  ssh access has only been tested with Git
1.7.10.

To test local access, run this command which creates the test-git
directory and creates some test data in it:

    ./test-git-setup.sh

Then run these four commands at the same time, preferably in separate
windows so that you can see their output:

      ./test-git-reclone.sh master
      ./test-git-reclone.sh mirror
      ./test-git-mirror.sh
      ./test-git-commit.sh

The commands should run forever (or until your disk fills up).  But
the test-git-reclone command exits after a while.  The stdout and
stderr from the "git clone" command is available in the
test-git/master.out, test-git/master.err, test-git/mirror.out and
test-git/mirror.err files.

To test via ssh, kill all the scripts, run this:

    ./test-git-setup.sh --use-ssh

and then restart the four test scripts.  This assumes that you have
things set up so that you can log in to localhost via ssh.  To avoid
locking errors from xauth, you should add these lines to the top of
.ssh/config while you are running this:

Host localhost
  ForwardX11 no
  ForwardX11Trusted no

When using the local protocol, the reclone script often fails after
just a few attempts, and I have never seen it handle more than 400
clones without getting an error.  When using ssh it is a lot harder to
trigger the problem.  I have only seen it 3 times out of more than
4000 attempts.