===Reproducing===
1. As User A, configure an externally-hosted repository to use Passphrase K1 (ssh key, only accessible to User A)
2. Import repository successfully
3. As User B, reconfigure the externally-hosted repository to update a new path where located.
4. See that importing will fail
In this scenario both User A and User B can manage the repository, however because Passphrase K1 can not be shared/used by any other user, when User B changed the path it appears that the K1 selection was removed from the configuration to pull.
I had already re-configured the affected repository so I could not confirm through db/local config whether a null credential was configured - only based on observation.
===Workaround===
Have User A reconfigure the externally-hosted repository to re-select K1 credentials and save. Schedule an update from web interface if necessary (it took a few weeks for us to realize it was not updated so the update frequency dropped significantly).
===Logs===
```lang=console,counterexample,name=/var/tmp/phd/log/daemons.log
,lines=10
[29-Jan-2016 12:07:26 America/New_York] [2016-01-29 12:07:26] EXCEPTION: (PhutilProxyException) Error while updating the "rSFST" repository. {>} (CommandException) Command failed with error #255!
COMMAND
'/usr/local/phacility/phabricator/bin/repository' update -- 'rSFST'
STDOUT
(empty)
STDERR
[2016-01-29 12:07:26] EXCEPTION: (Exception) Command failed with error #255!
COMMAND
hg --config ui.ssh='/usr/local/phacility/phabricator/bin/ssh-connect' pull -u -- 'xxxxx'
STDOUT
remote: Warning: Permanently added 'codehost.company.com,10.0.0.1' (RSA) to the list of known hosts.
remote: Permission denied, please try again.
remote: Permission denied, please try again.
remote: Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
STDERR
abort: no suitable response from remote hg!
at [<phabricator>/src/applications/repository/engine/PhabricatorRepositoryPullEngine.php:464]
arcanist(head=stable, ref.master=d54cb072facd, ref.stable=2412c31346ad), phabricator(head=stable, ref.master=7cc8a73d1efd, ref.stable=864d3984ebdb, custom=2), phutil(head=stable, ref.master=83f09f6c5a03, ref.stable=9c472e7c9b64)
#0 PhabricatorRepositoryPullEngine::executeMercurialUpdate() called at [<phabricator>/src/applications/repository/engine/PhabricatorRepositoryPullEngine.php:93]
... (567 more bytes) ... at [<phutil>/src/future/exec/ExecFuture.php:416]
[29-Jan-2016 12:07:26 America/New_York] arcanist(head=stable, ref.master=d54cb072facd, ref.stable=2412c31346ad), phabricator(head=stable, ref.master=7cc8a73d1efd, ref.stable=864d3984ebdb, custom=2), phutil(head=stable, ref.master=83f09f6c5a03, ref.stable=9c472e7c9b64)
[29-Jan-2016 12:07:26 America/New_York] #0 <#3> ExecFuture::resolvex() called at [<phabricator>/src/applications/repository/daemon/PhabricatorRepositoryPullLocalDaemon.php:374]
[29-Jan-2016 12:07:26 America/New_York] #1 phlog(PhutilProxyException) called at [<phabricator>/src/applications/repository/daemon/PhabricatorRepositoryPullLocalDaemon.php:381]
[29-Jan-2016 12:07:26 America/New_York] #2 PhabricatorRepositoryPullLocalDaemon::resolveUpdateFuture(PhabricatorRepository, ExecFuture, integer) called at [<phabricator>/src/applications/repository/daemon/PhabricatorRepositoryPullLocalDaemon.php:201]
[29-Jan-2016 12:07:26 America/New_York] #3 PhabricatorRepositoryPullLocalDaemon::run() called at [<phutil>/src/daemon/PhutilDaemon.php:183]
[29-Jan-2016 12:07:26 America/New_York] #4 PhutilDaemon::execute() called at [<phutil>/scripts/daemon/exec/exec_daemon.php:125]
```
===Install===
|libphutil|9c472e7c9b64395424c6cd25734bf239cb3c113d|
|arcanist|2412c31346add8be2a6acf18ebf812632b678f41|
|phabricator|864d3984ebdb42b9a2670103ca3607342e46b7dc|