`arc feature D123` should check out the branch from revision D123 according to the help:
> With __name__, it creates or checks out a branch. If the branch __name__ doesn't exist and is in format D123 then the branch of revision D123 is checked out.
I thought it would work kind of like `arc patch` but create a branch with a friendly name (instead of arcpatch-D123).
When I run it that doesn't seem to happen:
$ git branch
* master
$ arc feature D11892
Branch D11892 set up to track local branch master.
Switched to a new branch 'D11892'
$ git branch
* D11892
master
The new branch is just a tracking branch of master. The commits at D11892 and master are the same.
I added an `echo $ex` to ArcanistFeatureWorkflow.php:139 and saw the following error:
```
exception 'ConduitClientException' with message 'ERR-INVALID-SESSION: Session key is not present.' in /Users/elesh/Source/contrib/libphutil/src/conduit/ConduitFuture.php:54
Stack trace:
#0 /Users/elesh/Source/contrib/libphutil/src/future/FutureProxy.php(60): ConduitFuture->didReceiveResult(Array)
#1 /Users/elesh/Source/contrib/libphutil/src/future/FutureProxy.php(37): FutureProxy->getResult()
#2 /Users/elesh/Source/contrib/libphutil/src/conduit/ConduitClient.php(57): FutureProxy->resolve()
#3 /Users/elesh/Source/contrib/arcanist/src/workflow/ArcanistFeatureWorkflow.php(130): ConduitClient->callMethodSynchronous('differential.qu...', Array)
#4 /Users/elesh/Source/contrib/arcanist/src/workflow/ArcanistFeatureWorkflow.php(84): ArcanistFeatureWorkflow->checkoutBranch(Array)
#5 /Users/elesh/Source/contrib/arcanist/scripts/arcanist.php(378): ArcanistFeatureWorkflow->run()
#6 {main}
Branch D11892 set up to track local branch master.
Switched to a new branch 'D11892'
```
Versions
arcanist d8182cf55d501b1359f6f91bc0b75b50baa08037 (25 Feb 2015)
libphutil 124e5a41e0864ea68f7c921aafb01c5d457623a2 (25 Feb 2015)
Is this supposed to work, or have I misunderstood what it does?
For D11892 as used in the example above, I expected to see a branch named graceful-mod get created with the contents of the revision.