diff --git a/src/applications/harbormaster/controller/HarbormasterBuildLogRenderController.php b/src/applications/harbormaster/controller/HarbormasterBuildLogRenderController.php
index 50b17523ca..4b36ba83d9 100644
--- a/src/applications/harbormaster/controller/HarbormasterBuildLogRenderController.php
+++ b/src/applications/harbormaster/controller/HarbormasterBuildLogRenderController.php
@@ -1,668 +1,674 @@
 <?php
 
 final class HarbormasterBuildLogRenderController
   extends HarbormasterController {
 
   public function handleRequest(AphrontRequest $request) {
     $viewer = $this->getViewer();
 
     $id = $request->getURIData('id');
 
     $log = id(new HarbormasterBuildLogQuery())
       ->setViewer($viewer)
       ->withIDs(array($id))
       ->executeOne();
     if (!$log) {
       return new Aphront404Response();
     }
 
     $log_size = $this->getTotalByteLength($log);
 
     $head_lines = $request->getInt('head');
     if ($head_lines === null) {
       $head_lines = 8;
     }
     $head_lines = min($head_lines, 100);
     $head_lines = max($head_lines, 0);
 
     $tail_lines = $request->getInt('tail');
     if ($tail_lines === null) {
       $tail_lines = 16;
     }
     $tail_lines = min($tail_lines, 100);
     $tail_lines = max($tail_lines, 0);
 
     $head_offset = $request->getInt('headOffset');
     if ($head_offset === null) {
       $head_offset = 0;
     }
 
     $tail_offset = $request->getInt('tailOffset');
     if ($tail_offset === null) {
       $tail_offset = $log_size;
     }
 
     // Figure out which ranges we're actually going to read. We'll read either
     // one range (either just at the head, or just at the tail) or two ranges
     // (one at the head and one at the tail).
 
     // This gets a little bit tricky because: the ranges may overlap; we just
     // want to do one big read if there is only a little bit of text left
     // between the ranges; we may not know where the tail range ends; and we
     // can only read forward from line map markers, not from any arbitrary
     // position in the file.
 
     $bytes_per_line = 140;
     $body_lines = 8;
 
     $views = array();
     if ($head_lines > 0) {
       $views[] = array(
         'offset' => $head_offset,
         'lines' => $head_lines,
         'direction' => 1,
         'limit' => $tail_offset,
       );
     }
 
     if ($tail_lines > 0) {
       $views[] = array(
         'offset' => $tail_offset,
         'lines' => $tail_lines,
         'direction' => -1,
         'limit' => $head_offset,
       );
     }
 
     $reads = $views;
     foreach ($reads as $key => $read) {
       $offset = $read['offset'];
 
       $lines = $read['lines'];
 
       $read_length = 0;
       $read_length += ($lines * $bytes_per_line);
       $read_length += ($body_lines * $bytes_per_line);
 
       $direction = $read['direction'];
       if ($direction < 0) {
         $offset -= $read_length;
         if ($offset < 0) {
           $offset = 0;
           $read_length = $log_size;
         }
       }
 
       $position = $log->getReadPosition($offset);
       list($position_offset, $position_line) = $position;
       $read_length += ($offset - $position_offset);
 
       $reads[$key]['fetchOffset'] = $position_offset;
       $reads[$key]['fetchLength'] = $read_length;
       $reads[$key]['fetchLine'] = $position_line;
     }
 
     $reads = $this->mergeOverlappingReads($reads);
 
     foreach ($reads as $key => $read) {
-      $data = $log->loadData($read['fetchOffset'], $read['fetchLength']);
+      $fetch_offset = $read['fetchOffset'];
+      $fetch_length = $read['fetchLength'];
+      if ($fetch_offset + $fetch_length > $log_size) {
+        $fetch_length = $log_size - $fetch_offset;
+      }
+
+      $data = $log->loadData($fetch_offset, $fetch_length);
 
       $offset = $read['fetchOffset'];
       $line = $read['fetchLine'];
       $lines = $this->getLines($data);
       $line_data = array();
       foreach ($lines as $line_text) {
         $length = strlen($line_text);
         $line_data[] = array(
           'offset' => $offset,
           'length' => $length,
           'line' => $line,
           'data' => $line_text,
         );
         $line += 1;
         $offset += $length;
       }
 
       $reads[$key]['data'] = $data;
       $reads[$key]['lines'] = $line_data;
     }
 
     foreach ($views as $view_key => $view) {
       $anchor_byte = $view['offset'];
 
       if ($view['direction'] < 0) {
         $anchor_byte = $anchor_byte - 1;
       }
 
       $data_key = null;
       foreach ($reads as $read_key => $read) {
         $s = $read['fetchOffset'];
         $e = $s + $read['fetchLength'];
 
         if (($s <= $anchor_byte) && ($e >= $anchor_byte)) {
           $data_key = $read_key;
           break;
         }
       }
 
       if ($data_key === null) {
         throw new Exception(
           pht('Unable to find fetch!'));
       }
 
       $anchor_key = null;
       foreach ($reads[$data_key]['lines'] as $line_key => $line) {
         $s = $line['offset'];
         $e = $s + $line['length'];
 
         if (($s <= $anchor_byte) && ($e > $anchor_byte)) {
           $anchor_key = $line_key;
           break;
         }
       }
 
       if ($anchor_key === null) {
         throw new Exception(
           pht(
             'Unable to find lines.'));
       }
 
       if ($view['direction'] > 0) {
         $slice_offset = $anchor_key;
       } else {
         $slice_offset = max(0, $anchor_key - ($view['lines'] - 1));
       }
       $slice_length = $view['lines'];
 
       $views[$view_key] += array(
         'sliceKey' => $data_key,
         'sliceOffset' => $slice_offset,
         'sliceLength' => $slice_length,
       );
     }
 
     foreach ($views as $view_key => $view) {
       $slice_key = $view['sliceKey'];
       $lines = array_slice(
         $reads[$slice_key]['lines'],
         $view['sliceOffset'],
         $view['sliceLength']);
 
       $data_offset = null;
       $data_length = null;
       foreach ($lines as $line) {
         if ($data_offset === null) {
           $data_offset = $line['offset'];
         }
         $data_length += $line['length'];
       }
 
       // If the view cursor starts in the middle of a line, we're going to
       // strip part of the line.
       $direction = $view['direction'];
       if ($direction > 0) {
         $view_offset = $view['offset'];
         $view_length = $data_length;
         if ($data_offset < $view_offset) {
           $trim = ($view_offset - $data_offset);
           $view_length -= $trim;
         }
 
         $limit = $view['limit'];
         if ($limit < ($view_offset + $view_length)) {
           $view_length = ($limit - $view_offset);
         }
       } else {
         $view_offset = $data_offset;
         $view_length = $data_length;
         if ($data_offset + $data_length > $view['offset']) {
           $view_length -= (($data_offset + $data_length) - $view['offset']);
         }
 
         $limit = $view['limit'];
         if ($limit > $view_offset) {
           $view_length -= ($limit - $view_offset);
           $view_offset = $limit;
         }
       }
 
       $views[$view_key] += array(
         'viewOffset' => $view_offset,
         'viewLength' => $view_length,
       );
     }
 
     $views = $this->mergeOverlappingViews($views);
 
     foreach ($views as $view_key => $view) {
       $slice_key = $view['sliceKey'];
       $lines = array_slice(
         $reads[$slice_key]['lines'],
         $view['sliceOffset'],
         $view['sliceLength']);
 
       $view_offset = $view['viewOffset'];
       foreach ($lines as $line_key => $line) {
         $line_offset = $line['offset'];
 
         if ($line_offset >= $view_offset) {
           break;
         }
 
         $trim = ($view_offset - $line_offset);
         if ($trim && ($trim >= strlen($line['data']))) {
           unset($lines[$line_key]);
           continue;
         }
 
         $line_data = substr($line['data'], $trim);
         $lines[$line_key]['data'] = $line_data;
         $lines[$line_key]['length'] = strlen($line_data);
         $lines[$line_key]['offset'] += $trim;
         break;
       }
 
       $view_end = $view['viewOffset'] + $view['viewLength'];
       foreach ($lines as $line_key => $line) {
         $line_end = $line['offset'] + $line['length'];
         if ($line_end <= $view_end) {
           continue;
         }
 
         $trim = ($line_end - $view_end);
         if ($trim && ($trim >= strlen($line['data']))) {
           unset($lines[$line_key]);
           continue;
         }
 
         $line_data = substr($line['data'], -$trim);
         $lines[$line_key]['data'] = $line_data;
         $lines[$line_key]['length'] = strlen($line_data);
       }
 
       $views[$view_key]['viewData'] = $lines;
     }
 
     $spacer = null;
     $render = array();
 
     $head_view = head($views);
     if ($head_view['viewOffset'] > $head_offset) {
       $render[] = array(
         'spacer' => true,
         'head' => $head_offset,
         'tail' => $head_view['viewOffset'],
       );
     }
 
 
     foreach ($views as $view) {
       if ($spacer) {
         $spacer['tail'] = $view['viewOffset'];
         $render[] = $spacer;
       }
 
       $render[] = $view;
 
       $spacer = array(
         'spacer' => true,
         'head' => ($view['viewOffset'] + $view['viewLength']),
       );
     }
 
     $tail_view = last($views);
     if ($tail_view['viewOffset'] + $tail_view['viewLength'] < $tail_offset) {
       $render[] = array(
         'spacer' => true,
         'head' => $tail_view['viewOffset'] + $tail_view['viewLength'],
         'tail' => $tail_offset,
       );
     }
 
     $uri = $log->getURI();
     $highlight_range = $request->getURIData('lines');
 
     $rows = array();
     foreach ($render as $range) {
       if (isset($range['spacer'])) {
         $rows[] = $this->renderExpandRow($range);
         continue;
       }
 
       $lines = $range['viewData'];
       foreach ($lines as $line) {
         $display_line = ($line['line'] + 1);
         $display_text = ($line['data']);
 
         $display_line = phutil_tag(
           'a',
           array(
             'href' => $uri.'$'.$display_line,
           ),
           $display_line);
 
         $line_cell = phutil_tag('th', array(), $display_line);
         $text_cell = phutil_tag('td', array(), $display_text);
 
         $rows[] = phutil_tag(
           'tr',
           array(),
           array(
             $line_cell,
             $text_cell,
           ));
       }
     }
 
     $table = phutil_tag(
       'table',
       array(
         'class' => 'harbormaster-log-table PhabricatorMonospaced',
       ),
       $rows);
 
     // When this is a normal AJAX request, return the rendered log fragment
     // in an AJAX payload.
     if ($request->isAjax()) {
       return id(new AphrontAjaxResponse())
         ->setContent(
           array(
             'markup' => hsprintf('%s', $table),
           ));
     }
 
     // If the page is being accessed as a standalone page, present a
     // readable version of the fragment for debugging.
 
     require_celerity_resource('harbormaster-css');
 
     $header = pht('Standalone Log Fragment');
 
     $render_view = id(new PHUIObjectBoxView())
       ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
       ->setHeaderText($header)
       ->appendChild($table);
 
     $page_view = id(new PHUITwoColumnView())
       ->setFooter($render_view);
 
     $crumbs = $this->buildApplicationCrumbs()
       ->addTextCrumb(pht('Build Log %d', $log->getID()), $log->getURI())
       ->addTextCrumb(pht('Fragment'))
       ->setBorder(true);
 
     return $this->newPage()
       ->setTitle(
         array(
           pht('Build Log %d', $log->getID()),
           pht('Standalone Fragment'),
         ))
       ->setCrumbs($crumbs)
       ->appendChild($page_view);
   }
 
   private function getTotalByteLength(HarbormasterBuildLog $log) {
     $total_bytes = $log->getByteLength();
     if ($total_bytes) {
       return (int)$total_bytes;
     }
 
     // TODO: Remove this after enough time has passed for installs to run
     // log rebuilds or decide they don't care about older logs.
 
     // Older logs don't have this data denormalized onto the log record unless
     // an administrator has run `bin/harbormaster rebuild-log --all` or
     // similar. Try to figure it out by summing up the size of each chunk.
 
     // Note that the log may also be legitimately empty and have actual size
     // zero.
     $chunk = new HarbormasterBuildLogChunk();
     $conn = $chunk->establishConnection('r');
 
     $row = queryfx_one(
       $conn,
       'SELECT SUM(size) total FROM %T WHERE logID = %d',
       $chunk->getTableName(),
       $log->getID());
 
     return (int)$row['total'];
   }
 
   private function getLines($data) {
     $parts = preg_split("/(\r\n|\r|\n)/", $data, 0, PREG_SPLIT_DELIM_CAPTURE);
 
     if (last($parts) === '') {
       array_pop($parts);
     }
 
     $lines = array();
     for ($ii = 0; $ii < count($parts); $ii += 2) {
       $line = $parts[$ii];
       if (isset($parts[$ii + 1])) {
         $line .= $parts[$ii + 1];
       }
       $lines[] = $line;
     }
 
     return $lines;
   }
 
 
   private function mergeOverlappingReads(array $reads) {
     // Find planned reads which will overlap and merge them into a single
     // larger read.
 
     $uk = array_keys($reads);
     $vk = array_keys($reads);
 
     foreach ($uk as $ukey) {
       foreach ($vk as $vkey) {
         // Don't merge a range into itself, even though they do technically
         // overlap.
         if ($ukey === $vkey) {
           continue;
         }
 
         $uread = idx($reads, $ukey);
         if ($uread === null) {
           continue;
         }
 
         $vread = idx($reads, $vkey);
         if ($vread === null) {
           continue;
         }
 
         $us = $uread['fetchOffset'];
         $ue = $us + $uread['fetchLength'];
 
         $vs = $vread['fetchOffset'];
         $ve = $vs + $vread['fetchLength'];
 
         if (($vs > $ue) || ($ve < $us)) {
           continue;
         }
 
         $min = min($us, $vs);
         $max = max($ue, $ve);
 
         $reads[$ukey]['fetchOffset'] = $min;
         $reads[$ukey]['fetchLength'] = ($max - $min);
         $reads[$ukey]['fetchLine'] = min(
           $uread['fetchLine'],
           $vread['fetchLine']);
 
         unset($reads[$vkey]);
       }
     }
 
     return $reads;
   }
 
   private function mergeOverlappingViews(array $views) {
     $uk = array_keys($views);
     $vk = array_keys($views);
 
     $body_lines = 8;
     $body_bytes = ($body_lines * 140);
 
     foreach ($uk as $ukey) {
       foreach ($vk as $vkey) {
         if ($ukey === $vkey) {
           continue;
         }
 
         $uview = idx($views, $ukey);
         if ($uview === null) {
           continue;
         }
 
         $vview = idx($views, $vkey);
         if ($vview === null) {
           continue;
         }
 
         // If these views don't use the same line data, don't try to
         // merge them.
         if ($uview['sliceKey'] != $vview['sliceKey']) {
           continue;
         }
 
         // If these views are overlapping or separated by only a few bytes,
         // merge them into a single view.
         $us = $uview['viewOffset'];
         $ue = $us + $uview['viewLength'];
 
         $vs = $vview['viewOffset'];
         $ve = $vs + $vview['viewLength'];
 
         $uss = $uview['sliceOffset'];
         $use = $uss + $uview['sliceLength'];
 
         $vss = $vview['sliceOffset'];
         $vse = $vss + $vview['sliceLength'];
 
         if ($ue <= $vs) {
           if (($ue + $body_bytes) >= $vs) {
             if (($use + $body_lines) >= $vss) {
               $views[$ukey] = array(
                 'sliceLength' => ($vse - $uss),
                 'viewLength' => ($ve - $us),
               ) + $views[$ukey];
 
               unset($views[$vkey]);
               continue;
             }
           }
         }
       }
     }
 
     return $views;
   }
 
   private function renderExpandRow($range) {
 
     $icon_up = id(new PHUIIconView())
       ->setIcon('fa-chevron-up');
 
     $icon_down = id(new PHUIIconView())
       ->setIcon('fa-chevron-down');
 
     $up_text = array(
       pht('Show More Above'),
       ' ',
       $icon_up,
     );
 
     $expand_up = javelin_tag(
       'a',
       array(
         'sigil' => 'harbormaster-log-expand',
         'meta' => array(
           'headOffset' => $range['head'],
           'tailOffset' => $range['tail'],
           'head' => 4,
           'tail' => 0,
         ),
       ),
       $up_text);
 
     $mid_text = pht(
       'Show More (%s Bytes)',
       new PhutilNumber($range['tail'] - $range['head']));
 
     $expand_mid = javelin_tag(
       'a',
       array(
         'sigil' => 'harbormaster-log-expand',
         'meta' => array(
           'headOffset' => $range['head'],
           'tailOffset' => $range['tail'],
           'head' => 2,
           'tail' => 2,
         ),
       ),
       $mid_text);
 
     $down_text = array(
       $icon_down,
       ' ',
       pht('Show More Below'),
     );
 
     $expand_down = javelin_tag(
       'a',
       array(
         'sigil' => 'harbormaster-log-expand',
         'meta' => array(
           'headOffset' => $range['head'],
           'tailOffset' => $range['tail'],
           'head' => 0,
           'tail' => 4,
         ),
       ),
       $down_text);
 
     $expand_cells = array(
       phutil_tag(
         'td',
         array(
           'class' => 'harbormaster-log-expand-up',
         ),
         $expand_up),
       phutil_tag(
         'td',
         array(
           'class' => 'harbormaster-log-expand-mid',
         ),
         $expand_mid),
       phutil_tag(
         'td',
         array(
           'class' => 'harbormaster-log-expand-down',
         ),
         $expand_down),
     );
     $expand_row = phutil_tag('tr', array(), $expand_cells);
     $expand_table = phutil_tag(
       'table',
       array(
         'class' => 'harbormaster-log-expand-table',
       ),
       $expand_row);
 
     $cells = array(
       phutil_tag('th', array()),
       phutil_tag(
         'td',
         array(
           'class' => 'harbormaster-log-expand-cell',
         ),
         $expand_table),
     );
 
     return phutil_tag('tr', array(), $cells);
   }
 
 }
diff --git a/src/applications/harbormaster/controller/HarbormasterBuildLogViewController.php b/src/applications/harbormaster/controller/HarbormasterBuildLogViewController.php
index 41f2aef8e5..40641795c5 100644
--- a/src/applications/harbormaster/controller/HarbormasterBuildLogViewController.php
+++ b/src/applications/harbormaster/controller/HarbormasterBuildLogViewController.php
@@ -1,44 +1,50 @@
 <?php
 
 final class HarbormasterBuildLogViewController
   extends HarbormasterController {
 
   public function handleRequest(AphrontRequest $request) {
     $viewer = $this->getViewer();
 
     $id = $request->getURIData('id');
 
     $log = id(new HarbormasterBuildLogQuery())
       ->setViewer($viewer)
       ->withIDs(array($id))
       ->executeOne();
     if (!$log) {
       return new Aphront404Response();
     }
 
+    $target = $log->getBuildTarget();
+    $build = $target->getBuild();
+
     $page_title = pht('Build Log %d', $log->getID());
 
     $log_view = id(new HarbormasterBuildLogView())
       ->setViewer($viewer)
       ->setBuildLog($log)
       ->setHighlightedLineRange($request->getURIData('lines'));
 
     $crumbs = $this->buildApplicationCrumbs()
       ->addTextCrumb(pht('Build Logs'))
+      ->addTextCrumb(
+        pht('Build %d', $build->getID()),
+        $build->getURI())
       ->addTextCrumb($page_title)
       ->setBorder(true);
 
     $page_header = id(new PHUIHeaderView())
       ->setHeader($page_title);
 
     $page_view = id(new PHUITwoColumnView())
       ->setHeader($page_header)
       ->setFooter($log_view);
 
     return $this->newPage()
       ->setTitle($page_title)
       ->setCrumbs($crumbs)
       ->appendChild($page_view);
   }
 
 }
diff --git a/src/applications/harbormaster/controller/HarbormasterBuildViewController.php b/src/applications/harbormaster/controller/HarbormasterBuildViewController.php
index 4507139d47..0e09b4d658 100644
--- a/src/applications/harbormaster/controller/HarbormasterBuildViewController.php
+++ b/src/applications/harbormaster/controller/HarbormasterBuildViewController.php
@@ -1,667 +1,674 @@
 <?php
 
 final class HarbormasterBuildViewController
   extends HarbormasterController {
 
   public function handleRequest(AphrontRequest $request) {
     $request = $this->getRequest();
     $viewer = $request->getUser();
 
     $id = $request->getURIData('id');
     $generation = $request->getInt('g');
 
     $build = id(new HarbormasterBuildQuery())
       ->setViewer($viewer)
       ->withIDs(array($id))
       ->executeOne();
     if (!$build) {
       return new Aphront404Response();
     }
 
     require_celerity_resource('harbormaster-css');
 
     $title = pht('Build %d', $id);
 
     $page_header = id(new PHUIHeaderView())
       ->setHeader($title)
       ->setUser($viewer)
       ->setPolicyObject($build)
       ->setHeaderIcon('fa-cubes');
 
     if ($build->isRestarting()) {
       $page_header->setStatus(
         'fa-exclamation-triangle', 'red', pht('Restarting'));
     } else if ($build->isPausing()) {
       $page_header->setStatus(
         'fa-exclamation-triangle', 'red', pht('Pausing'));
     } else if ($build->isResuming()) {
       $page_header->setStatus(
         'fa-exclamation-triangle', 'red', pht('Resuming'));
     } else if ($build->isAborting()) {
       $page_header->setStatus(
         'fa-exclamation-triangle', 'red', pht('Aborting'));
     }
 
     $curtain = $this->buildCurtainView($build);
     $properties = $this->buildPropertyList($build);
 
     $crumbs = $this->buildApplicationCrumbs();
     $this->addBuildableCrumb($crumbs, $build->getBuildable());
     $crumbs->addTextCrumb($title);
     $crumbs->setBorder(true);
 
     if ($generation === null || $generation > $build->getBuildGeneration() ||
       $generation < 0) {
       $generation = $build->getBuildGeneration();
     }
 
     $build_targets = id(new HarbormasterBuildTargetQuery())
       ->setViewer($viewer)
       ->needBuildSteps(true)
       ->withBuildPHIDs(array($build->getPHID()))
       ->withBuildGenerations(array($generation))
       ->execute();
 
     if ($build_targets) {
       $messages = id(new HarbormasterBuildMessageQuery())
         ->setViewer($viewer)
         ->withReceiverPHIDs(mpull($build_targets, 'getPHID'))
         ->execute();
       $messages = mgroup($messages, 'getReceiverPHID');
     } else {
       $messages = array();
     }
 
     if ($build_targets) {
       $artifacts = id(new HarbormasterBuildArtifactQuery())
         ->setViewer($viewer)
         ->withBuildTargetPHIDs(mpull($build_targets, 'getPHID'))
         ->execute();
       $artifacts = msort($artifacts, 'getArtifactKey');
       $artifacts = mgroup($artifacts, 'getBuildTargetPHID');
     } else {
       $artifacts = array();
     }
 
 
     $targets = array();
     foreach ($build_targets as $build_target) {
       $header = id(new PHUIHeaderView())
         ->setHeader($build_target->getName())
         ->setUser($viewer)
         ->setHeaderIcon('fa-bullseye');
 
       $target_box = id(new PHUIObjectBoxView())
         ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
         ->setHeader($header);
 
       $tab_group = new PHUITabGroupView();
       $target_box->addTabGroup($tab_group);
 
       $property_list = new PHUIPropertyListView();
 
       $target_artifacts = idx($artifacts, $build_target->getPHID(), array());
 
       $links = array();
       $type_uri = HarbormasterURIArtifact::ARTIFACTCONST;
       foreach ($target_artifacts as $artifact) {
         if ($artifact->getArtifactType() == $type_uri) {
           $impl = $artifact->getArtifactImplementation();
           if ($impl->isExternalLink()) {
             $links[] = $impl->renderLink();
           }
         }
       }
 
       if ($links) {
         $links = phutil_implode_html(phutil_tag('br'), $links);
         $property_list->addProperty(
           pht('External Link'),
           $links);
       }
 
       $status_view = new PHUIStatusListView();
       $item = new PHUIStatusItemView();
 
       $status = $build_target->getTargetStatus();
       $status_name =
         HarbormasterBuildTarget::getBuildTargetStatusName($status);
       $icon = HarbormasterBuildTarget::getBuildTargetStatusIcon($status);
       $color = HarbormasterBuildTarget::getBuildTargetStatusColor($status);
 
       $item->setTarget($status_name);
       $item->setIcon($icon, $color);
       $status_view->addItem($item);
 
       $when = array();
       $started = $build_target->getDateStarted();
       $now = PhabricatorTime::getNow();
       if ($started) {
         $ended = $build_target->getDateCompleted();
         if ($ended) {
           $when[] = pht(
             'Completed at %s',
             phabricator_datetime($ended, $viewer));
 
           $duration = ($ended - $started);
           if ($duration) {
             $when[] = pht(
               'Built for %s',
               phutil_format_relative_time_detailed($duration));
           } else {
             $when[] = pht('Built instantly');
           }
         } else {
           $when[] = pht(
             'Started at %s',
             phabricator_datetime($started, $viewer));
           $duration = ($now - $started);
           if ($duration) {
             $when[] = pht(
               'Running for %s',
               phutil_format_relative_time_detailed($duration));
           }
         }
       } else {
         $created = $build_target->getDateCreated();
         $when[] = pht(
           'Queued at %s',
           phabricator_datetime($started, $viewer));
         $duration = ($now - $created);
         if ($duration) {
           $when[] = pht(
             'Waiting for %s',
             phutil_format_relative_time_detailed($duration));
         }
       }
 
       $property_list->addProperty(
         pht('When'),
         phutil_implode_html(" \xC2\xB7 ", $when));
 
       $property_list->addProperty(pht('Status'), $status_view);
 
       $tab_group->addTab(
         id(new PHUITabView())
           ->setName(pht('Overview'))
           ->setKey('overview')
           ->appendChild($property_list));
 
       $step = $build_target->getBuildStep();
 
       if ($step) {
         $description = $step->getDescription();
         if ($description) {
           $description = new PHUIRemarkupView($viewer, $description);
           $property_list->addSectionHeader(
             pht('Description'), PHUIPropertyListView::ICON_SUMMARY);
           $property_list->addTextContent($description);
         }
       } else {
         $target_box->setFormErrors(
           array(
             pht(
               'This build step has since been deleted on the build plan.  '.
               'Some information may be omitted.'),
           ));
       }
 
       $details = $build_target->getDetails();
       $property_list = new PHUIPropertyListView();
       foreach ($details as $key => $value) {
         $property_list->addProperty($key, $value);
       }
       $tab_group->addTab(
         id(new PHUITabView())
           ->setName(pht('Configuration'))
           ->setKey('configuration')
           ->appendChild($property_list));
 
       $variables = $build_target->getVariables();
       $variables_tab = $this->buildProperties($variables);
       $tab_group->addTab(
         id(new PHUITabView())
           ->setName(pht('Variables'))
           ->setKey('variables')
           ->appendChild($variables_tab));
 
       $artifacts_tab = $this->buildArtifacts($build_target, $target_artifacts);
       $tab_group->addTab(
         id(new PHUITabView())
           ->setName(pht('Artifacts'))
           ->setKey('artifacts')
           ->appendChild($artifacts_tab));
 
       $build_messages = idx($messages, $build_target->getPHID(), array());
       $messages_tab = $this->buildMessages($build_messages);
       $tab_group->addTab(
         id(new PHUITabView())
           ->setName(pht('Messages'))
           ->setKey('messages')
           ->appendChild($messages_tab));
 
       $property_list = new PHUIPropertyListView();
       $property_list->addProperty(
         pht('Build Target ID'),
         $build_target->getID());
       $property_list->addProperty(
         pht('Build Target PHID'),
         $build_target->getPHID());
 
       $tab_group->addTab(
         id(new PHUITabView())
           ->setName(pht('Metadata'))
           ->setKey('metadata')
           ->appendChild($property_list));
 
       $targets[] = $target_box;
 
       $targets[] = $this->buildLog($build, $build_target);
     }
 
     $timeline = $this->buildTransactionTimeline(
       $build,
       new HarbormasterBuildTransactionQuery());
     $timeline->setShouldTerminate(true);
 
     $view = id(new PHUITwoColumnView())
       ->setHeader($page_header)
       ->setCurtain($curtain)
       ->setMainColumn(array(
         $properties,
         $targets,
         $timeline,
       ));
 
     return $this->newPage()
       ->setTitle($title)
       ->setCrumbs($crumbs)
       ->appendChild($view);
 
   }
 
   private function buildArtifacts(
     HarbormasterBuildTarget $build_target,
     array $artifacts) {
     $viewer = $this->getViewer();
 
     $rows = array();
     foreach ($artifacts as $artifact) {
       $impl = $artifact->getArtifactImplementation();
 
       if ($impl) {
         $summary = $impl->renderArtifactSummary($viewer);
         $type_name = $impl->getArtifactTypeName();
       } else {
         $summary = pht('<Unknown Artifact Type>');
         $type_name = $artifact->getType();
       }
 
       $rows[] = array(
         $artifact->getArtifactKey(),
         $type_name,
         $summary,
       );
     }
 
     $table = id(new AphrontTableView($rows))
       ->setNoDataString(pht('This target has no associated artifacts.'))
       ->setHeaders(
         array(
           pht('Key'),
           pht('Type'),
           pht('Summary'),
         ))
       ->setColumnClasses(
         array(
           'pri',
           '',
           'wide',
         ));
 
     return $table;
   }
 
   private function buildLog(
     HarbormasterBuild $build,
     HarbormasterBuildTarget $build_target) {
 
     $request = $this->getRequest();
     $viewer = $request->getUser();
     $limit = $request->getInt('l', 25);
 
     $logs = id(new HarbormasterBuildLogQuery())
       ->setViewer($viewer)
       ->withBuildTargetPHIDs(array($build_target->getPHID()))
       ->execute();
 
     $empty_logs = array();
 
     $log_boxes = array();
     foreach ($logs as $log) {
       $start = 1;
       $lines = preg_split("/\r\n|\r|\n/", $log->getLogText());
       if ($limit !== 0) {
         $start = count($lines) - $limit;
         if ($start >= 1) {
           $lines = array_slice($lines, -$limit, $limit);
         } else {
           $start = 1;
         }
       }
 
       $id = null;
       $is_empty = false;
       if (count($lines) === 1 && trim($lines[0]) === '') {
         // Prevent Harbormaster from showing empty build logs.
         $id = celerity_generate_unique_node_id();
         $empty_logs[] = $id;
         $is_empty = true;
       }
 
       $log_view = new ShellLogView();
       $log_view->setLines($lines);
       $log_view->setStart($start);
 
+      $prototype_view = id(new PHUIButtonView())
+        ->setTag('a')
+        ->setHref($log->getURI())
+        ->setIcon('fa-file-text-o')
+        ->setText(pht('New View (Prototype)'));
+
       $header = id(new PHUIHeaderView())
         ->setHeader(pht(
           'Build Log %d (%s - %s)',
           $log->getID(),
           $log->getLogSource(),
           $log->getLogType()))
+        ->addActionLink($prototype_view)
         ->setSubheader($this->createLogHeader($build, $log))
         ->setUser($viewer);
 
       $log_box = id(new PHUIObjectBoxView())
         ->setHeader($header)
         ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
         ->setForm($log_view);
 
       if ($is_empty) {
         $log_box = phutil_tag(
           'div',
           array(
             'style' => 'display: none',
             'id' => $id,
           ),
           $log_box);
       }
 
       $log_boxes[] = $log_box;
     }
 
     if ($empty_logs) {
       $hide_id = celerity_generate_unique_node_id();
 
       Javelin::initBehavior('phabricator-reveal-content');
 
       $expand = phutil_tag(
         'div',
         array(
           'id' => $hide_id,
           'class' => 'harbormaster-empty-logs-are-hidden',
         ),
         array(
           pht(
             '%s empty logs are hidden.',
             phutil_count($empty_logs)),
           ' ',
           javelin_tag(
             'a',
             array(
               'href' => '#',
               'sigil' => 'reveal-content',
               'meta' => array(
                 'showIDs' => $empty_logs,
                 'hideIDs' => array($hide_id),
               ),
             ),
             pht('Show all logs.')),
         ));
 
       array_unshift($log_boxes, $expand);
     }
 
     return $log_boxes;
   }
 
   private function createLogHeader($build, $log) {
     $request = $this->getRequest();
     $limit = $request->getInt('l', 25);
 
     $lines_25 = $this->getApplicationURI('/build/'.$build->getID().'/?l=25');
     $lines_50 = $this->getApplicationURI('/build/'.$build->getID().'/?l=50');
     $lines_100 =
       $this->getApplicationURI('/build/'.$build->getID().'/?l=100');
     $lines_0 = $this->getApplicationURI('/build/'.$build->getID().'/?l=0');
 
     $link_25 = phutil_tag('a', array('href' => $lines_25), pht('25'));
     $link_50 = phutil_tag('a', array('href' => $lines_50), pht('50'));
     $link_100 = phutil_tag('a', array('href' => $lines_100), pht('100'));
     $link_0 = phutil_tag('a', array('href' => $lines_0), pht('Unlimited'));
 
     if ($limit === 25) {
       $link_25 = phutil_tag('strong', array(), $link_25);
     } else if ($limit === 50) {
       $link_50 = phutil_tag('strong', array(), $link_50);
     } else if ($limit === 100) {
       $link_100 = phutil_tag('strong', array(), $link_100);
     } else if ($limit === 0) {
       $link_0 = phutil_tag('strong', array(), $link_0);
     }
 
     return phutil_tag(
       'span',
       array(),
       array(
         $link_25,
         ' - ',
         $link_50,
         ' - ',
         $link_100,
         ' - ',
         $link_0,
         ' Lines',
       ));
   }
 
   private function buildCurtainView(HarbormasterBuild $build) {
     $viewer = $this->getViewer();
     $id = $build->getID();
 
     $curtain = $this->newCurtainView($build);
 
     $can_restart =
       $build->canRestartBuild() &&
       $build->canIssueCommand(
         $viewer,
         HarbormasterBuildCommand::COMMAND_RESTART);
 
     $can_pause =
       $build->canPauseBuild() &&
       $build->canIssueCommand(
         $viewer,
         HarbormasterBuildCommand::COMMAND_PAUSE);
 
     $can_resume =
       $build->canResumeBuild() &&
       $build->canIssueCommand(
         $viewer,
         HarbormasterBuildCommand::COMMAND_RESUME);
 
     $can_abort =
       $build->canAbortBuild() &&
       $build->canIssueCommand(
         $viewer,
         HarbormasterBuildCommand::COMMAND_ABORT);
 
     $curtain->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('Restart Build'))
         ->setIcon('fa-repeat')
         ->setHref($this->getApplicationURI('/build/restart/'.$id.'/'))
         ->setDisabled(!$can_restart)
         ->setWorkflow(true));
 
     if ($build->canResumeBuild()) {
       $curtain->addAction(
         id(new PhabricatorActionView())
           ->setName(pht('Resume Build'))
           ->setIcon('fa-play')
           ->setHref($this->getApplicationURI('/build/resume/'.$id.'/'))
           ->setDisabled(!$can_resume)
           ->setWorkflow(true));
     } else {
       $curtain->addAction(
         id(new PhabricatorActionView())
           ->setName(pht('Pause Build'))
           ->setIcon('fa-pause')
           ->setHref($this->getApplicationURI('/build/pause/'.$id.'/'))
           ->setDisabled(!$can_pause)
           ->setWorkflow(true));
     }
 
     $curtain->addAction(
       id(new PhabricatorActionView())
         ->setName(pht('Abort Build'))
         ->setIcon('fa-exclamation-triangle')
         ->setHref($this->getApplicationURI('/build/abort/'.$id.'/'))
         ->setDisabled(!$can_abort)
         ->setWorkflow(true));
 
     return $curtain;
   }
 
   private function buildPropertyList(HarbormasterBuild $build) {
     $viewer = $this->getViewer();
 
     $properties = id(new PHUIPropertyListView())
       ->setUser($viewer);
 
     $handles = id(new PhabricatorHandleQuery())
       ->setViewer($viewer)
       ->withPHIDs(array(
         $build->getBuildablePHID(),
         $build->getBuildPlanPHID(),
       ))
       ->execute();
 
     $properties->addProperty(
       pht('Buildable'),
       $handles[$build->getBuildablePHID()]->renderLink());
 
     $properties->addProperty(
       pht('Build Plan'),
       $handles[$build->getBuildPlanPHID()]->renderLink());
 
     $properties->addProperty(
       pht('Restarts'),
       $build->getBuildGeneration());
 
     $properties->addProperty(
       pht('Status'),
       $this->getStatus($build));
 
     return id(new PHUIObjectBoxView())
       ->setHeaderText(pht('Properties'))
       ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
       ->appendChild($properties);
 
   }
 
   private function getStatus(HarbormasterBuild $build) {
     $status_view = new PHUIStatusListView();
 
     $item = new PHUIStatusItemView();
 
     if ($build->isPausing()) {
       $status_name = pht('Pausing');
       $icon = PHUIStatusItemView::ICON_RIGHT;
       $color = 'dark';
     } else {
       $status = $build->getBuildStatus();
       $status_name =
         HarbormasterBuildStatus::getBuildStatusName($status);
       $icon = HarbormasterBuildStatus::getBuildStatusIcon($status);
       $color = HarbormasterBuildStatus::getBuildStatusColor($status);
     }
 
     $item->setTarget($status_name);
     $item->setIcon($icon, $color);
     $status_view->addItem($item);
 
     return $status_view;
   }
 
   private function buildMessages(array $messages) {
     $viewer = $this->getRequest()->getUser();
 
     if ($messages) {
       $handles = id(new PhabricatorHandleQuery())
         ->setViewer($viewer)
         ->withPHIDs(mpull($messages, 'getAuthorPHID'))
         ->execute();
     } else {
       $handles = array();
     }
 
     $rows = array();
     foreach ($messages as $message) {
       $rows[] = array(
         $message->getID(),
         $handles[$message->getAuthorPHID()]->renderLink(),
         $message->getType(),
         $message->getIsConsumed() ? pht('Consumed') : null,
         phabricator_datetime($message->getDateCreated(), $viewer),
       );
     }
 
     $table = new AphrontTableView($rows);
     $table->setNoDataString(pht('No messages for this build target.'));
     $table->setHeaders(
       array(
         pht('ID'),
         pht('From'),
         pht('Type'),
         pht('Consumed'),
         pht('Received'),
       ));
     $table->setColumnClasses(
       array(
         '',
         '',
         'wide',
         '',
         'date',
       ));
 
     return $table;
   }
 
   private function buildProperties(array $properties) {
     ksort($properties);
 
     $rows = array();
     foreach ($properties as $key => $value) {
       $rows[] = array(
         $key,
         $value,
       );
     }
 
     $table = id(new AphrontTableView($rows))
       ->setHeaders(
         array(
           pht('Key'),
           pht('Value'),
         ))
       ->setColumnClasses(
         array(
           'pri right',
           'wide',
         ));
 
     return $table;
   }
 
 }
diff --git a/src/applications/harbormaster/view/HarbormasterBuildLogView.php b/src/applications/harbormaster/view/HarbormasterBuildLogView.php
index 81705f3f49..e240aab510 100644
--- a/src/applications/harbormaster/view/HarbormasterBuildLogView.php
+++ b/src/applications/harbormaster/view/HarbormasterBuildLogView.php
@@ -1,73 +1,88 @@
 <?php
 
 final class HarbormasterBuildLogView extends AphrontView {
 
   private $log;
   private $highlightedLineRange;
 
   public function setBuildLog(HarbormasterBuildLog $log) {
     $this->log = $log;
     return $this;
   }
 
   public function getBuildLog() {
     return $this->log;
   }
 
   public function setHighlightedLineRange($range) {
     $this->highlightedLineRange = $range;
     return $this;
   }
 
   public function getHighlightedLineRange() {
     return $this->highlightedLineRange;
   }
 
   public function render() {
     $viewer = $this->getViewer();
     $log = $this->getBuildLog();
     $id = $log->getID();
 
     $header = id(new PHUIHeaderView())
       ->setViewer($viewer)
       ->setHeader(pht('Build Log %d', $id));
 
     $download_uri = "/harbormaster/log/download/{$id}/";
 
     $download_button = id(new PHUIButtonView())
       ->setTag('a')
       ->setHref($download_uri)
       ->setIcon('fa-download')
       ->setDisabled(!$log->getFilePHID())
       ->setWorkflow(true)
       ->setText(pht('Download Log'));
 
     $header->addActionLink($download_button);
 
-    $content_id = celerity_generate_unique_node_id();
-    $content_div = javelin_tag(
-      'div',
-      array(
-        'id' => $content_id,
-        'class' => 'harbormaster-log-view-loading',
-      ),
-      pht('Loading...'));
-
-    require_celerity_resource('harbormaster-css');
-
-    Javelin::initBehavior(
-      'harbormaster-log',
-      array(
-        'contentNodeID' => $content_id,
-        'renderURI' => $log->getRenderURI($this->getHighlightedLineRange()),
-      ));
-
     $box_view = id(new PHUIObjectBoxView())
       ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY)
-      ->setHeader($header)
-      ->appendChild($content_div);
+      ->setHeader($header);
+
+    $has_linemap = $log->getLineMap();
+    if ($has_linemap) {
+      $content_id = celerity_generate_unique_node_id();
+      $content_div = javelin_tag(
+        'div',
+        array(
+          'id' => $content_id,
+          'class' => 'harbormaster-log-view-loading',
+        ),
+        pht('Loading...'));
+
+      require_celerity_resource('harbormaster-css');
+
+      Javelin::initBehavior(
+        'harbormaster-log',
+        array(
+          'contentNodeID' => $content_id,
+          'renderURI' => $log->getRenderURI($this->getHighlightedLineRange()),
+        ));
+
+      $box_view->appendChild($content_div);
+    } else {
+      $box_view->setFormErrors(
+        array(
+          pht(
+            'This older log is missing required rendering data. To rebuild '.
+            'rendering data, run: %s',
+            phutil_tag(
+              'tt',
+              array(),
+              '$ bin/harbormaster rebuild-log --force --id '.$log->getID())),
+        ));
+    }
 
     return $box_view;
   }
 
 }