propose-requirements-updates fails with git rebase errors

[Jeremy Stanley]

This has been happening for a couple months.

[...]
+ git commit --amend -a -F-
[review/jenkins/openstack/requirements 09567e7] Updated from global requirements
2 files changed, 8 insertions(+), 9 deletions(-)
+ git review -t openstack/requirements master
Errors running git rebase -i remotes/gerrit/master
Rebasing (1/1)
error: could not apply 09567e7... Updated from global requirements

When you have resolved this problem run "git rebase --continue".
[...]

http://logs.openstack.org/d6/d627576b50473cae501acd7124114a31099e7484/post/propose-requirements-updates/f1bc252/console.html

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/69946

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/69969
Committed: https://git.openstack.org/cgit/openstack-infra/config/commit/?id=1059461c6c11d6745f1d5890eb2c15194746e378
Submitter: Jenkins
Branch: master

commit 1059461c6c11d6745f1d5890eb2c15194746e378
Author: Clark Boylan <email address hidden>
Date: Wed Jan 29 12:44:31 2014 -0800

    Make requirement update proposals more robust.

    When proposing requirement update changes ensure that the proper branch
    can be checked out if the branch isn't master. To do this checkout
    origin/$BRANCH instead of just branch. Additonally, don't git review -d
    an existing change as it may have merge conflicts with the target
    branch. Instead make changes against the target branch, push them to the
    existing change as a new patchset, and ignore failures of git review
    when there are no new changes.

    This allows changes to the requirements files to happen out of band from
    these automated change proposals.

    Closes-Bug: 1274251
    Change-Id: I7b81b87a90639a66dce5502cded5e37d96abd1f7