diff --git a/src/applications/harbormaster/step/HarbormasterWaitForPreviousBuildStepImplementation.php b/src/applications/harbormaster/step/HarbormasterWaitForPreviousBuildStepImplementation.php
index 7f63eda072..eadf4c94f5 100644
--- a/src/applications/harbormaster/step/HarbormasterWaitForPreviousBuildStepImplementation.php
+++ b/src/applications/harbormaster/step/HarbormasterWaitForPreviousBuildStepImplementation.php
@@ -1,115 +1,98 @@
 <?php
 
 final class HarbormasterWaitForPreviousBuildStepImplementation
   extends HarbormasterBuildStepImplementation {
 
   public function getName() {
     return pht('Wait for Previous Commits to Build');
   }
 
   public function getGenericDescription() {
     return pht(
       'Wait for previous commits to finish building the current plan '.
       'before continuing.');
   }
 
   public function getBuildStepGroupKey() {
     return HarbormasterPrototypeBuildStepGroup::GROUPKEY;
   }
 
   public function execute(
     HarbormasterBuild $build,
     HarbormasterBuildTarget $build_target) {
 
     // We can only wait when building against commits.
     $buildable = $build->getBuildable();
     $object = $buildable->getBuildableObject();
     if (!($object instanceof PhabricatorRepositoryCommit)) {
       return;
     }
 
     // Block until all previous builds of the same build plan have
     // finished.
     $plan = $build->getBuildPlan();
-
-    $existing_logs = id(new HarbormasterBuildLogQuery())
-      ->setViewer(PhabricatorUser::getOmnipotentUser())
-      ->withBuildTargetPHIDs(array($build_target->getPHID()))
-      ->execute();
-
-    if ($existing_logs) {
-      $log = head($existing_logs);
-    } else {
-      $log = $build->createLog($build_target, 'waiting', 'blockers');
-    }
-
     $blockers = $this->getBlockers($object, $plan, $build);
-    if ($blockers) {
-      $log->start();
-      $log->append(pht("Blocked by: %s\n", implode(',', $blockers)));
-      $log->finalize();
-    }
 
     if ($blockers) {
       throw new PhabricatorWorkerYieldException(15);
     }
   }
 
   private function getBlockers(
     PhabricatorRepositoryCommit $commit,
     HarbormasterBuildPlan $plan,
     HarbormasterBuild $source) {
 
     $call = new ConduitCall(
       'diffusion.commitparentsquery',
       array(
         'commit' => $commit->getCommitIdentifier(),
         'repository' => $commit->getRepository()->getPHID(),
       ));
     $call->setUser(PhabricatorUser::getOmnipotentUser());
     $parents = $call->execute();
 
     $parents = id(new DiffusionCommitQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withRepository($commit->getRepository())
       ->withIdentifiers($parents)
       ->execute();
 
     $blockers = array();
 
     $build_objects = array();
     foreach ($parents as $parent) {
       if (!$parent->isImported()) {
         $blockers[] = pht('Commit %s', $parent->getCommitIdentifier());
       } else {
         $build_objects[] = $parent->getPHID();
       }
     }
 
     if ($build_objects) {
       $buildables = id(new HarbormasterBuildableQuery())
         ->setViewer(PhabricatorUser::getOmnipotentUser())
         ->withBuildablePHIDs($build_objects)
         ->withManualBuildables(false)
         ->execute();
       $buildable_phids = mpull($buildables, 'getPHID');
 
       if ($buildable_phids) {
         $builds = id(new HarbormasterBuildQuery())
           ->setViewer(PhabricatorUser::getOmnipotentUser())
           ->withBuildablePHIDs($buildable_phids)
           ->withBuildPlanPHIDs(array($plan->getPHID()))
           ->execute();
 
         foreach ($builds as $build) {
           if (!$build->isComplete()) {
             $blockers[] = pht('Build %d', $build->getID());
           }
         }
       }
     }
 
     return $blockers;
   }
 
 }
diff --git a/src/applications/harbormaster/storage/build/HarbormasterBuild.php b/src/applications/harbormaster/storage/build/HarbormasterBuild.php
index 5134d0efa0..4d9278c7bf 100644
--- a/src/applications/harbormaster/storage/build/HarbormasterBuild.php
+++ b/src/applications/harbormaster/storage/build/HarbormasterBuild.php
@@ -1,542 +1,525 @@
 <?php
 
 final class HarbormasterBuild extends HarbormasterDAO
   implements
     PhabricatorApplicationTransactionInterface,
     PhabricatorPolicyInterface {
 
   protected $buildablePHID;
   protected $buildPlanPHID;
   protected $buildStatus;
   protected $buildGeneration;
   protected $buildParameters = array();
   protected $initiatorPHID;
   protected $planAutoKey;
 
   private $buildable = self::ATTACHABLE;
   private $buildPlan = self::ATTACHABLE;
   private $buildTargets = self::ATTACHABLE;
   private $unprocessedCommands = self::ATTACHABLE;
 
   /**
    * Not currently being built.
    */
   const STATUS_INACTIVE = 'inactive';
 
   /**
    * Pending pick up by the Harbormaster daemon.
    */
   const STATUS_PENDING = 'pending';
 
   /**
    * Current building the buildable.
    */
   const STATUS_BUILDING = 'building';
 
   /**
    * The build has passed.
    */
   const STATUS_PASSED = 'passed';
 
   /**
    * The build has failed.
    */
   const STATUS_FAILED = 'failed';
 
   /**
    * The build has aborted.
    */
   const STATUS_ABORTED = 'aborted';
 
   /**
    * The build encountered an unexpected error.
    */
   const STATUS_ERROR = 'error';
 
   /**
    * The build has been paused.
    */
   const STATUS_PAUSED = 'paused';
 
   /**
    * The build has been deadlocked.
    */
   const STATUS_DEADLOCKED = 'deadlocked';
 
 
   /**
    * Get a human readable name for a build status constant.
    *
    * @param  const  Build status constant.
    * @return string Human-readable name.
    */
   public static function getBuildStatusName($status) {
     switch ($status) {
       case self::STATUS_INACTIVE:
         return pht('Inactive');
       case self::STATUS_PENDING:
         return pht('Pending');
       case self::STATUS_BUILDING:
         return pht('Building');
       case self::STATUS_PASSED:
         return pht('Passed');
       case self::STATUS_FAILED:
         return pht('Failed');
       case self::STATUS_ABORTED:
         return pht('Aborted');
       case self::STATUS_ERROR:
         return pht('Unexpected Error');
       case self::STATUS_PAUSED:
         return pht('Paused');
       case self::STATUS_DEADLOCKED:
         return pht('Deadlocked');
       default:
         return pht('Unknown');
     }
   }
 
   public static function getBuildStatusIcon($status) {
     switch ($status) {
       case self::STATUS_INACTIVE:
       case self::STATUS_PENDING:
         return PHUIStatusItemView::ICON_OPEN;
       case self::STATUS_BUILDING:
         return PHUIStatusItemView::ICON_RIGHT;
       case self::STATUS_PASSED:
         return PHUIStatusItemView::ICON_ACCEPT;
       case self::STATUS_FAILED:
         return PHUIStatusItemView::ICON_REJECT;
       case self::STATUS_ABORTED:
         return PHUIStatusItemView::ICON_MINUS;
       case self::STATUS_ERROR:
         return PHUIStatusItemView::ICON_MINUS;
       case self::STATUS_PAUSED:
         return PHUIStatusItemView::ICON_MINUS;
       case self::STATUS_DEADLOCKED:
         return PHUIStatusItemView::ICON_WARNING;
       default:
         return PHUIStatusItemView::ICON_QUESTION;
     }
   }
 
   public static function getBuildStatusColor($status) {
     switch ($status) {
       case self::STATUS_INACTIVE:
         return 'dark';
       case self::STATUS_PENDING:
       case self::STATUS_BUILDING:
         return 'blue';
       case self::STATUS_PASSED:
         return 'green';
       case self::STATUS_FAILED:
       case self::STATUS_ABORTED:
       case self::STATUS_ERROR:
       case self::STATUS_DEADLOCKED:
         return 'red';
       case self::STATUS_PAUSED:
         return 'dark';
       default:
         return 'bluegrey';
     }
   }
 
   public static function initializeNewBuild(PhabricatorUser $actor) {
     return id(new HarbormasterBuild())
       ->setBuildStatus(self::STATUS_INACTIVE)
       ->setBuildGeneration(0);
   }
 
   public function delete() {
     $this->openTransaction();
       $this->deleteUnprocessedCommands();
       $result = parent::delete();
     $this->saveTransaction();
 
     return $result;
   }
 
   protected function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_SERIALIZATION => array(
         'buildParameters' => self::SERIALIZATION_JSON,
       ),
       self::CONFIG_COLUMN_SCHEMA => array(
         'buildStatus' => 'text32',
         'buildGeneration' => 'uint32',
         'planAutoKey' => 'text32?',
         'initiatorPHID' => 'phid?',
       ),
       self::CONFIG_KEY_SCHEMA => array(
         'key_buildable' => array(
           'columns' => array('buildablePHID'),
         ),
         'key_plan' => array(
           'columns' => array('buildPlanPHID'),
         ),
         'key_status' => array(
           'columns' => array('buildStatus'),
         ),
         'key_planautokey' => array(
           'columns' => array('buildablePHID', 'planAutoKey'),
           'unique' => true,
         ),
       ),
     ) + parent::getConfiguration();
   }
 
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       HarbormasterBuildPHIDType::TYPECONST);
   }
 
   public function attachBuildable(HarbormasterBuildable $buildable) {
     $this->buildable = $buildable;
     return $this;
   }
 
   public function getBuildable() {
     return $this->assertAttached($this->buildable);
   }
 
   public function getName() {
     if ($this->getBuildPlan()) {
       return $this->getBuildPlan()->getName();
     }
     return pht('Build');
   }
 
   public function attachBuildPlan(
     HarbormasterBuildPlan $build_plan = null) {
     $this->buildPlan = $build_plan;
     return $this;
   }
 
   public function getBuildPlan() {
     return $this->assertAttached($this->buildPlan);
   }
 
   public function getBuildTargets() {
     return $this->assertAttached($this->buildTargets);
   }
 
   public function attachBuildTargets(array $targets) {
     $this->buildTargets = $targets;
     return $this;
   }
 
   public function isBuilding() {
     return $this->getBuildStatus() === self::STATUS_PENDING ||
       $this->getBuildStatus() === self::STATUS_BUILDING;
   }
 
   public function isAutobuild() {
     return ($this->getPlanAutoKey() !== null);
   }
 
-  public function createLog(
-    HarbormasterBuildTarget $build_target,
-    $log_source,
-    $log_type) {
-
-    $log_source = id(new PhutilUTF8StringTruncator())
-      ->setMaximumBytes(250)
-      ->truncateString($log_source);
-
-    $log = HarbormasterBuildLog::initializeNewBuildLog($build_target)
-      ->setLogSource($log_source)
-      ->setLogType($log_type)
-      ->save();
-
-    return $log;
-  }
-
   public function retrieveVariablesFromBuild() {
     $results = array(
       'buildable.diff' => null,
       'buildable.revision' => null,
       'buildable.commit' => null,
       'repository.callsign' => null,
       'repository.phid' => null,
       'repository.vcs' => null,
       'repository.uri' => null,
       'step.timestamp' => null,
       'build.id' => null,
       'initiator.phid' => null,
     );
 
     foreach ($this->getBuildParameters() as $key => $value) {
       $results['build/'.$key] = $value;
     }
 
     $buildable = $this->getBuildable();
     $object = $buildable->getBuildableObject();
 
     $object_variables = $object->getBuildVariables();
 
     $results = $object_variables + $results;
 
     $results['step.timestamp'] = time();
     $results['build.id'] = $this->getID();
     $results['initiator.phid'] = $this->getInitiatorPHID();
 
     return $results;
   }
 
   public static function getAvailableBuildVariables() {
     $objects = id(new PhutilClassMapQuery())
       ->setAncestorClass('HarbormasterBuildableInterface')
       ->execute();
 
     $variables = array();
     $variables[] = array(
       'step.timestamp' => pht('The current UNIX timestamp.'),
       'build.id' => pht('The ID of the current build.'),
       'target.phid' => pht('The PHID of the current build target.'),
       'initiator.phid' => pht(
         'The PHID of the user or Object that initiated the build, '.
         'if applicable.'),
     );
 
     foreach ($objects as $object) {
       $variables[] = $object->getAvailableBuildVariables();
     }
 
     $variables = array_mergev($variables);
     return $variables;
   }
 
   public function isComplete() {
     switch ($this->getBuildStatus()) {
       case self::STATUS_PASSED:
       case self::STATUS_FAILED:
       case self::STATUS_ABORTED:
       case self::STATUS_ERROR:
       case self::STATUS_PAUSED:
         return true;
     }
 
     return false;
   }
 
   public function isPaused() {
     return ($this->getBuildStatus() == self::STATUS_PAUSED);
   }
 
   public function getURI() {
     $id = $this->getID();
     return "/harbormaster/build/{$id}/";
   }
 
 
 /* -(  Build Commands  )----------------------------------------------------- */
 
 
   private function getUnprocessedCommands() {
     return $this->assertAttached($this->unprocessedCommands);
   }
 
   public function attachUnprocessedCommands(array $commands) {
     $this->unprocessedCommands = $commands;
     return $this;
   }
 
   public function canRestartBuild() {
     if ($this->isAutobuild()) {
       return false;
     }
 
     return !$this->isRestarting();
   }
 
   public function canPauseBuild() {
     if ($this->isAutobuild()) {
       return false;
     }
 
     return !$this->isComplete() &&
            !$this->isPaused() &&
            !$this->isPausing();
   }
 
   public function canAbortBuild() {
     if ($this->isAutobuild()) {
       return false;
     }
 
     return !$this->isComplete();
   }
 
   public function canResumeBuild() {
     if ($this->isAutobuild()) {
       return false;
     }
 
     return $this->isPaused() &&
            !$this->isResuming();
   }
 
   public function isPausing() {
     $is_pausing = false;
     foreach ($this->getUnprocessedCommands() as $command_object) {
       $command = $command_object->getCommand();
       switch ($command) {
         case HarbormasterBuildCommand::COMMAND_PAUSE:
           $is_pausing = true;
           break;
         case HarbormasterBuildCommand::COMMAND_RESUME:
         case HarbormasterBuildCommand::COMMAND_RESTART:
           $is_pausing = false;
           break;
         case HarbormasterBuildCommand::COMMAND_ABORT:
           $is_pausing = true;
           break;
       }
     }
 
     return $is_pausing;
   }
 
   public function isResuming() {
     $is_resuming = false;
     foreach ($this->getUnprocessedCommands() as $command_object) {
       $command = $command_object->getCommand();
       switch ($command) {
         case HarbormasterBuildCommand::COMMAND_RESTART:
         case HarbormasterBuildCommand::COMMAND_RESUME:
           $is_resuming = true;
           break;
         case HarbormasterBuildCommand::COMMAND_PAUSE:
           $is_resuming = false;
           break;
         case HarbormasterBuildCommand::COMMAND_ABORT:
           $is_resuming = false;
           break;
       }
     }
 
     return $is_resuming;
   }
 
   public function isRestarting() {
     $is_restarting = false;
     foreach ($this->getUnprocessedCommands() as $command_object) {
       $command = $command_object->getCommand();
       switch ($command) {
         case HarbormasterBuildCommand::COMMAND_RESTART:
           $is_restarting = true;
           break;
       }
     }
 
     return $is_restarting;
   }
 
   public function isAborting() {
     $is_aborting = false;
     foreach ($this->getUnprocessedCommands() as $command_object) {
       $command = $command_object->getCommand();
       switch ($command) {
         case HarbormasterBuildCommand::COMMAND_ABORT:
           $is_aborting = true;
           break;
       }
     }
 
     return $is_aborting;
   }
 
   public function deleteUnprocessedCommands() {
     foreach ($this->getUnprocessedCommands() as $key => $command_object) {
       $command_object->delete();
       unset($this->unprocessedCommands[$key]);
     }
 
     return $this;
   }
 
   public function canIssueCommand(PhabricatorUser $viewer, $command) {
     try {
       $this->assertCanIssueCommand($viewer, $command);
       return true;
     } catch (Exception $ex) {
       return false;
     }
   }
 
   public function assertCanIssueCommand(PhabricatorUser $viewer, $command) {
     $need_edit = false;
     switch ($command) {
       case HarbormasterBuildCommand::COMMAND_RESTART:
         break;
       case HarbormasterBuildCommand::COMMAND_PAUSE:
       case HarbormasterBuildCommand::COMMAND_RESUME:
       case HarbormasterBuildCommand::COMMAND_ABORT:
         $need_edit = true;
         break;
       default:
         throw new Exception(
           pht(
             'Invalid Harbormaster build command "%s".',
             $command));
     }
 
     // Issuing these commands requires that you be able to edit the build, to
     // prevent enemy engineers from sabotaging your builds. See T9614.
     if ($need_edit) {
       PhabricatorPolicyFilter::requireCapability(
         $viewer,
         $this->getBuildPlan(),
         PhabricatorPolicyCapability::CAN_EDIT);
     }
   }
 
 
 /* -(  PhabricatorApplicationTransactionInterface  )------------------------- */
 
 
   public function getApplicationTransactionEditor() {
     return new HarbormasterBuildTransactionEditor();
   }
 
   public function getApplicationTransactionObject() {
     return $this;
   }
 
   public function getApplicationTransactionTemplate() {
     return new HarbormasterBuildTransaction();
   }
 
   public function willRenderTimeline(
     PhabricatorApplicationTransactionView $timeline,
     AphrontRequest $request) {
 
     return $timeline;
   }
 
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
       PhabricatorPolicyCapability::CAN_EDIT,
     );
   }
 
   public function getPolicy($capability) {
     return $this->getBuildable()->getPolicy($capability);
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
     return $this->getBuildable()->hasAutomaticCapability(
       $capability,
       $viewer);
   }
 
   public function describeAutomaticCapability($capability) {
     return pht('A build inherits policies from its buildable.');
   }
 
 }
diff --git a/src/applications/harbormaster/storage/build/HarbormasterBuildLog.php b/src/applications/harbormaster/storage/build/HarbormasterBuildLog.php
index 85e7ae2411..8b7c5c85bb 100644
--- a/src/applications/harbormaster/storage/build/HarbormasterBuildLog.php
+++ b/src/applications/harbormaster/storage/build/HarbormasterBuildLog.php
@@ -1,220 +1,221 @@
 <?php
 
-final class HarbormasterBuildLog extends HarbormasterDAO
+final class HarbormasterBuildLog
+  extends HarbormasterDAO
   implements PhabricatorPolicyInterface {
 
   protected $buildTargetPHID;
   protected $logSource;
   protected $logType;
   protected $duration;
   protected $live;
 
   private $buildTarget = self::ATTACHABLE;
-  private $start;
 
   const CHUNK_BYTE_LIMIT = 102400;
 
   /**
    * The log is encoded as plain text.
    */
   const ENCODING_TEXT = 'text';
 
   public function __destruct() {
-    if ($this->start) {
-      $this->finalize($this->start);
+    if ($this->getLive()) {
+      $this->closeBuildLog();
     }
   }
 
   public static function initializeNewBuildLog(
     HarbormasterBuildTarget $build_target) {
 
     return id(new HarbormasterBuildLog())
       ->setBuildTargetPHID($build_target->getPHID())
       ->setDuration(null)
       ->setLive(0);
   }
 
+  public function openBuildLog() {
+    if ($this->getLive()) {
+      throw new Exception(pht('This build log is already open!'));
+    }
+
+    return $this
+      ->setLive(1)
+      ->save();
+  }
+
+  public function closeBuildLog() {
+    if (!$this->getLive()) {
+      throw new Exception(pht('This build log is not open!'));
+    }
+
+    // TODO: Encode the log contents in a gzipped format.
+
+    $this->reload();
+
+    $start = $this->getDateCreated();
+    $now = PhabricatorTime::getNow();
+
+    return $this
+      ->setDuration($now - $start)
+      ->setLive(0)
+      ->save();
+  }
+
+
   protected function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_COLUMN_SCHEMA => array(
         // T6203/NULLABILITY
         // It seems like these should be non-nullable? All logs should have a
         // source, etc.
         'logSource' => 'text255?',
         'logType' => 'text255?',
         'duration' => 'uint32?',
 
         'live' => 'bool',
       ),
       self::CONFIG_KEY_SCHEMA => array(
         'key_buildtarget' => array(
           'columns' => array('buildTargetPHID'),
         ),
       ),
     ) + parent::getConfiguration();
   }
 
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       HarbormasterBuildLogPHIDType::TYPECONST);
   }
 
   public function attachBuildTarget(HarbormasterBuildTarget $build_target) {
     $this->buildTarget = $build_target;
     return $this;
   }
 
   public function getBuildTarget() {
     return $this->assertAttached($this->buildTarget);
   }
 
   public function getName() {
     return pht('Build Log');
   }
 
-  public function start() {
-    if ($this->getLive()) {
-      throw new Exception(
-        pht('Live logging has already started for this log.'));
-    }
-
-    $this->setLive(1);
-    $this->save();
-
-    $this->start = PhabricatorTime::getNow();
-
-    return time();
-  }
-
   public function append($content) {
     if (!$this->getLive()) {
-      throw new Exception(
-        pht('Start logging before appending data to the log.'));
+      throw new PhutilInvalidStateException('openBuildLog');
     }
-    if (strlen($content) === 0) {
+
+    $content = (string)$content;
+    if (!strlen($content)) {
       return;
     }
 
     // If the length of the content is greater than the chunk size limit,
     // then we can never fit the content in a single record. We need to
     // split our content out and call append on it for as many parts as there
     // are to the content.
     if (strlen($content) > self::CHUNK_BYTE_LIMIT) {
       $current = $content;
       while (strlen($current) > self::CHUNK_BYTE_LIMIT) {
         $part = substr($current, 0, self::CHUNK_BYTE_LIMIT);
         $current = substr($current, self::CHUNK_BYTE_LIMIT);
         $this->append($part);
       }
       $this->append($current);
       return;
     }
 
     // Retrieve the size of last chunk from the DB for this log. If the
     // chunk is over 500K, then we need to create a new log entry.
     $conn = $this->establishConnection('w');
     $result = queryfx_all(
       $conn,
       'SELECT id, size, encoding '.
       'FROM harbormaster_buildlogchunk '.
       'WHERE logID = %d '.
       'ORDER BY id DESC '.
       'LIMIT 1',
       $this->getID());
     if (count($result) === 0 ||
       $result[0]['size'] + strlen($content) > self::CHUNK_BYTE_LIMIT ||
       $result[0]['encoding'] !== self::ENCODING_TEXT) {
 
       // We must insert a new chunk because the data we are appending
       // won't fit into the existing one, or we don't have any existing
       // chunk data.
       queryfx(
         $conn,
         'INSERT INTO harbormaster_buildlogchunk '.
         '(logID, encoding, size, chunk) '.
         'VALUES '.
         '(%d, %s, %d, %B)',
         $this->getID(),
         self::ENCODING_TEXT,
         strlen($content),
         $content);
     } else {
       // We have a resulting record that we can append our content onto.
       queryfx(
         $conn,
         'UPDATE harbormaster_buildlogchunk '.
         'SET chunk = CONCAT(chunk, %B), size = LENGTH(CONCAT(chunk, %B))'.
         'WHERE id = %d',
         $content,
         $content,
         $result[0]['id']);
     }
   }
 
-  public function finalize($start = 0) {
-    if (!$this->getLive()) {
-      // TODO: Clean up this API.
-      return;
-    }
-
-    // TODO: Encode the log contents in a gzipped format.
-    $this->reload();
-    if ($start > 0) {
-      $this->setDuration(time() - $start);
-    }
-    $this->setLive(0);
-    $this->save();
-  }
-
   public function getLogText() {
     // TODO: This won't cope very well if we're pulling like a 700MB
     // log file out of the DB. We should probably implement some sort
     // of optional limit parameter so that when we're rendering out only
     // 25 lines in the UI, we don't wastefully read in the whole log.
 
     // We have to read our content out of the database and stitch all of
     // the log data back together.
     $conn = $this->establishConnection('r');
     $result = queryfx_all(
       $conn,
       'SELECT chunk '.
       'FROM harbormaster_buildlogchunk '.
       'WHERE logID = %d '.
       'ORDER BY id ASC',
       $this->getID());
 
     $content = '';
     foreach ($result as $row) {
       $content .= $row['chunk'];
     }
     return $content;
   }
 
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
     );
   }
 
   public function getPolicy($capability) {
     return $this->getBuildTarget()->getPolicy($capability);
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
     return $this->getBuildTarget()->hasAutomaticCapability(
       $capability,
       $viewer);
   }
 
   public function describeAutomaticCapability($capability) {
     return pht(
       "Users must be able to see a build target to view it's build log.");
   }
 
 
 }
diff --git a/src/applications/harbormaster/storage/build/HarbormasterBuildTarget.php b/src/applications/harbormaster/storage/build/HarbormasterBuildTarget.php
index 27655189e6..8b47bdfc21 100644
--- a/src/applications/harbormaster/storage/build/HarbormasterBuildTarget.php
+++ b/src/applications/harbormaster/storage/build/HarbormasterBuildTarget.php
@@ -1,358 +1,357 @@
 <?php
 
 final class HarbormasterBuildTarget extends HarbormasterDAO
   implements PhabricatorPolicyInterface {
 
   protected $name;
   protected $buildPHID;
   protected $buildStepPHID;
   protected $className;
   protected $details;
   protected $variables;
   protected $targetStatus;
   protected $dateStarted;
   protected $dateCompleted;
   protected $buildGeneration;
 
   const STATUS_PENDING = 'target/pending';
   const STATUS_BUILDING = 'target/building';
   const STATUS_WAITING = 'target/waiting';
   const STATUS_PASSED = 'target/passed';
   const STATUS_FAILED = 'target/failed';
   const STATUS_ABORTED = 'target/aborted';
 
   private $build = self::ATTACHABLE;
   private $buildStep = self::ATTACHABLE;
   private $implementation;
 
   public static function getBuildTargetStatusName($status) {
     switch ($status) {
       case self::STATUS_PENDING:
         return pht('Pending');
       case self::STATUS_BUILDING:
         return pht('Building');
       case self::STATUS_WAITING:
         return pht('Waiting for Message');
       case self::STATUS_PASSED:
         return pht('Passed');
       case self::STATUS_FAILED:
         return pht('Failed');
       case self::STATUS_ABORTED:
         return pht('Aborted');
       default:
         return pht('Unknown');
     }
   }
 
   public static function getBuildTargetStatusIcon($status) {
     switch ($status) {
       case self::STATUS_PENDING:
         return PHUIStatusItemView::ICON_OPEN;
       case self::STATUS_BUILDING:
       case self::STATUS_WAITING:
         return PHUIStatusItemView::ICON_RIGHT;
       case self::STATUS_PASSED:
         return PHUIStatusItemView::ICON_ACCEPT;
       case self::STATUS_FAILED:
         return PHUIStatusItemView::ICON_REJECT;
       case self::STATUS_ABORTED:
         return PHUIStatusItemView::ICON_MINUS;
       default:
         return PHUIStatusItemView::ICON_QUESTION;
     }
   }
 
   public static function getBuildTargetStatusColor($status) {
     switch ($status) {
       case self::STATUS_PENDING:
       case self::STATUS_BUILDING:
       case self::STATUS_WAITING:
         return 'blue';
       case self::STATUS_PASSED:
         return 'green';
       case self::STATUS_FAILED:
       case self::STATUS_ABORTED:
         return 'red';
       default:
         return 'bluegrey';
     }
   }
 
   public static function initializeNewBuildTarget(
     HarbormasterBuild $build,
     HarbormasterBuildStep $build_step,
     array $variables) {
     return id(new HarbormasterBuildTarget())
       ->setName($build_step->getName())
       ->setBuildPHID($build->getPHID())
       ->setBuildStepPHID($build_step->getPHID())
       ->setClassName($build_step->getClassName())
       ->setDetails($build_step->getDetails())
       ->setTargetStatus(self::STATUS_PENDING)
       ->setVariables($variables)
       ->setBuildGeneration($build->getBuildGeneration());
   }
 
   protected function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_SERIALIZATION => array(
         'details' => self::SERIALIZATION_JSON,
         'variables' => self::SERIALIZATION_JSON,
       ),
       self::CONFIG_COLUMN_SCHEMA => array(
         'className' => 'text255',
         'targetStatus' => 'text64',
         'dateStarted' => 'epoch?',
         'dateCompleted' => 'epoch?',
         'buildGeneration' => 'uint32',
 
         // T6203/NULLABILITY
         // This should not be nullable.
         'name' => 'text255?',
       ),
       self::CONFIG_KEY_SCHEMA => array(
         'key_build' => array(
           'columns' => array('buildPHID', 'buildStepPHID'),
         ),
       ),
     ) + parent::getConfiguration();
   }
 
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       HarbormasterBuildTargetPHIDType::TYPECONST);
   }
 
   public function attachBuild(HarbormasterBuild $build) {
     $this->build = $build;
     return $this;
   }
 
   public function getBuild() {
     return $this->assertAttached($this->build);
   }
 
   public function attachBuildStep(HarbormasterBuildStep $step = null) {
     $this->buildStep = $step;
     return $this;
   }
 
   public function getBuildStep() {
     return $this->assertAttached($this->buildStep);
   }
 
   public function getDetail($key, $default = null) {
     return idx($this->details, $key, $default);
   }
 
   public function setDetail($key, $value) {
     $this->details[$key] = $value;
     return $this;
   }
 
   public function getVariables() {
     return parent::getVariables() + $this->getBuildTargetVariables();
   }
 
   public function getVariable($key, $default = null) {
     return idx($this->variables, $key, $default);
   }
 
   public function setVariable($key, $value) {
     $this->variables[$key] = $value;
     return $this;
   }
 
   public function getImplementation() {
     if ($this->implementation === null) {
       $obj = HarbormasterBuildStepImplementation::requireImplementation(
         $this->className);
       $obj->loadSettings($this);
       $this->implementation = $obj;
     }
 
     return $this->implementation;
   }
 
   public function isAutotarget() {
     try {
       return (bool)$this->getImplementation()->getBuildStepAutotargetPlanKey();
     } catch (Exception $e) {
       return false;
     }
   }
 
   public function getName() {
     if (strlen($this->name) && !$this->isAutotarget()) {
       return $this->name;
     }
 
     try {
       return $this->getImplementation()->getName();
     } catch (Exception $e) {
       return $this->getClassName();
     }
   }
 
   private function getBuildTargetVariables() {
     return array(
       'target.phid' => $this->getPHID(),
     );
   }
 
   public function createArtifact(
     PhabricatorUser $actor,
     $artifact_key,
     $artifact_type,
     array $artifact_data) {
 
     $impl = HarbormasterArtifact::getArtifactType($artifact_type);
     if (!$impl) {
       throw new Exception(
         pht(
           'There is no implementation available for artifacts of type "%s".',
           $artifact_type));
     }
 
     $impl->validateArtifactData($artifact_data);
 
     $artifact = HarbormasterBuildArtifact::initializeNewBuildArtifact($this)
       ->setArtifactKey($artifact_key)
       ->setArtifactType($artifact_type)
       ->setArtifactData($artifact_data);
 
     $impl = $artifact->getArtifactImplementation();
     $impl->willCreateArtifact($actor);
 
     return $artifact->save();
   }
 
   public function loadArtifact($artifact_key) {
     $indexes = array();
 
     $indexes[] = HarbormasterBuildArtifact::getArtifactIndex(
       $this,
       $artifact_key);
 
     $artifact = id(new HarbormasterBuildArtifactQuery())
       ->setViewer(PhabricatorUser::getOmnipotentUser())
       ->withArtifactIndexes($indexes)
       ->executeOne();
     if ($artifact === null) {
       throw new Exception(
         pht(
           'Artifact "%s" not found!',
           $artifact_key));
     }
 
     return $artifact;
   }
 
   public function newLog($log_source, $log_type) {
     $log_source = id(new PhutilUTF8StringTruncator())
       ->setMaximumBytes(250)
       ->truncateString($log_source);
 
     $log = HarbormasterBuildLog::initializeNewBuildLog($this)
       ->setLogSource($log_source)
-      ->setLogType($log_type);
-
-    $log->start();
+      ->setLogType($log_type)
+      ->openBuildLog();
 
     return $log;
   }
 
   public function getFieldValue($key) {
     $field_list = PhabricatorCustomField::getObjectFields(
       $this->getBuildStep(),
       PhabricatorCustomField::ROLE_VIEW);
 
     $fields = $field_list->getFields();
     $full_key = "std:harbormaster:core:{$key}";
 
     $field = idx($fields, $full_key);
     if (!$field) {
       throw new Exception(
         pht(
           'Unknown build step field "%s"!',
           $key));
     }
 
     $field = clone $field;
     $field->setValueFromStorage($this->getDetail($key));
     return $field->getBuildTargetFieldValue();
   }
 
 
 
 /* -(  Status  )------------------------------------------------------------- */
 
 
   public function isComplete() {
     switch ($this->getTargetStatus()) {
       case self::STATUS_PASSED:
       case self::STATUS_FAILED:
       case self::STATUS_ABORTED:
         return true;
     }
 
     return false;
   }
 
 
   public function isFailed() {
     switch ($this->getTargetStatus()) {
       case self::STATUS_FAILED:
       case self::STATUS_ABORTED:
         return true;
     }
 
     return false;
   }
 
 
   public function isWaiting() {
     switch ($this->getTargetStatus()) {
       case self::STATUS_WAITING:
         return true;
     }
 
     return false;
   }
 
   public function isUnderway() {
     switch ($this->getTargetStatus()) {
       case self::STATUS_PENDING:
       case self::STATUS_BUILDING:
         return true;
     }
 
     return false;
   }
 
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
     );
   }
 
   public function getPolicy($capability) {
     return $this->getBuild()->getPolicy($capability);
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
     return $this->getBuild()->hasAutomaticCapability(
       $capability,
       $viewer);
   }
 
   public function describeAutomaticCapability($capability) {
     return pht('Users must be able to see a build to view its build targets.');
   }
 
 }
diff --git a/src/applications/harbormaster/worker/HarbormasterTargetWorker.php b/src/applications/harbormaster/worker/HarbormasterTargetWorker.php
index ac3014dc29..fa3a01272b 100644
--- a/src/applications/harbormaster/worker/HarbormasterTargetWorker.php
+++ b/src/applications/harbormaster/worker/HarbormasterTargetWorker.php
@@ -1,115 +1,112 @@
 <?php
 
 /**
  * Execute a build target.
  */
 final class HarbormasterTargetWorker extends HarbormasterWorker {
 
   public function getRequiredLeaseTime() {
     // This worker performs actual build work, which may involve a long wait
     // on external systems.
     return phutil_units('24 hours in seconds');
   }
 
   public function renderForDisplay(PhabricatorUser $viewer) {
     try {
       $target = $this->loadBuildTarget();
     } catch (Exception $ex) {
       return null;
     }
 
     return $viewer->renderHandle($target->getPHID());
   }
 
   private function loadBuildTarget() {
     $data = $this->getTaskData();
     $id = idx($data, 'targetID');
 
     $target = id(new HarbormasterBuildTargetQuery())
       ->withIDs(array($id))
       ->setViewer($this->getViewer())
       ->needBuildSteps(true)
       ->executeOne();
 
     if (!$target) {
       throw new PhabricatorWorkerPermanentFailureException(
         pht(
           'Bad build target ID "%d".',
           $id));
     }
 
     return $target;
   }
 
   protected function doWork() {
     $target = $this->loadBuildTarget();
     $build = $target->getBuild();
     $viewer = $this->getViewer();
 
     $target->setDateStarted(time());
 
     try {
       if ($target->getBuildGeneration() !== $build->getBuildGeneration()) {
         throw new HarbormasterBuildAbortedException();
       }
 
       $status_pending = HarbormasterBuildTarget::STATUS_PENDING;
       if ($target->getTargetStatus() == $status_pending) {
         $target->setTargetStatus(HarbormasterBuildTarget::STATUS_BUILDING);
         $target->save();
       }
 
       $implementation = $target->getImplementation();
       $implementation->setCurrentWorkerTaskID($this->getCurrentWorkerTaskID());
       $implementation->execute($build, $target);
 
       $next_status = HarbormasterBuildTarget::STATUS_PASSED;
       if ($implementation->shouldWaitForMessage($target)) {
         $next_status = HarbormasterBuildTarget::STATUS_WAITING;
       }
 
       $target->setTargetStatus($next_status);
 
       if ($target->isComplete()) {
         $target->setDateCompleted(PhabricatorTime::getNow());
       }
 
       $target->save();
     } catch (PhabricatorWorkerYieldException $ex) {
       // If the target wants to yield, let that escape without further
       // processing. We'll resume after the task retries.
       throw $ex;
     } catch (HarbormasterBuildFailureException $ex) {
       // A build step wants to fail explicitly.
       $target->setTargetStatus(HarbormasterBuildTarget::STATUS_FAILED);
       $target->setDateCompleted(PhabricatorTime::getNow());
       $target->save();
     } catch (HarbormasterBuildAbortedException $ex) {
       // A build step is aborting because the build has been restarted.
       $target->setTargetStatus(HarbormasterBuildTarget::STATUS_ABORTED);
       $target->setDateCompleted(PhabricatorTime::getNow());
       $target->save();
     } catch (Exception $ex) {
-      phlog($ex);
-
       try {
-        $log = $build->createLog($target, 'core', 'exception');
-        $start = $log->start();
-        $log->append((string)$ex);
-        $log->finalize($start);
+        $log = $target->newLog('core', 'exception')
+          ->append($ex)
+          ->closeBuildLog();
       } catch (Exception $log_ex) {
         phlog($log_ex);
       }
 
       $target->setTargetStatus(HarbormasterBuildTarget::STATUS_FAILED);
       $target->setDateCompleted(time());
       $target->save();
     }
 
     id(new HarbormasterBuildEngine())
       ->setViewer($viewer)
       ->setBuild($build)
       ->continueBuild();
   }
 
 }