$ git checkout -b upstreamtest --track
Branch upstreamtest set up to track local branch master.
Switched to a new branch 'upstreamtest'
$ echo a >> README ; git commit -am dummy
[upstreamtest 1e6b8d0] dummy
1 file changed, 1 insertion(+)
$ arc which --base arc:upstream
REPOSITORY
To identify the repository associated with this working copy, arc followed this process:
Configuration value "repository.callsign" is empty.
Configuration value "project.name" is set to "phabricator"; this project
is associated with the "P" repository.
Found a unique matching repository.
This working copy is associated with the P repository.
COMMIT RANGE
If you run 'arc diff', changes between the commit:
fe29db6b92de8d5a Use shouldAllowPublic(), not shouldRequireLogin(), for Legalpad
...and the current working copy state will be sent to Differential, because
it is the merge-base of the upstream of the current branch and HEAD, and
matched the rule 'arc:upstream' in your runtime 'base' configuration.
You can see the exact changes that will be sent by running this command:
$ git diff fe29db6b92de8d5a..HEAD
These commits will be included in the diff:
1e6b8d000ed71567 dummy
MATCHING REVISIONS
These Differential revisions match the changes in this working copy:
(No revisions match.)
Since there are no revisions in Differential which match this working copy, a
new revision will be created if you run 'arc diff'.
$