diff --git a/resources/celerity/map.php b/resources/celerity/map.php
--- a/resources/celerity/map.php
+++ b/resources/celerity/map.php
@@ -75,7 +75,7 @@
     'rsrc/css/application/feed/feed.css' => 'ecd4ec57',
     'rsrc/css/application/files/global-drag-and-drop.css' => 'b556a948',
     'rsrc/css/application/flag/flag.css' => 'bba8f811',
-    'rsrc/css/application/harbormaster/harbormaster.css' => '730a4a3c',
+    'rsrc/css/application/harbormaster/harbormaster.css' => '7446ce72',
     'rsrc/css/application/herald/herald-test.css' => 'a52e323e',
     'rsrc/css/application/herald/herald.css' => 'cd8d0134',
     'rsrc/css/application/maniphest/report.css' => '9b9580b7',
@@ -554,7 +554,7 @@
     'font-fontawesome' => 'e838e088',
     'font-lato' => 'c7ccd872',
     'global-drag-and-drop-css' => 'b556a948',
-    'harbormaster-css' => '730a4a3c',
+    'harbormaster-css' => '7446ce72',
     'herald-css' => 'cd8d0134',
     'herald-rule-editor' => 'dca75c0e',
     'herald-test-css' => 'a52e323e',
diff --git a/src/applications/differential/controller/DifferentialRevisionViewController.php b/src/applications/differential/controller/DifferentialRevisionViewController.php
--- a/src/applications/differential/controller/DifferentialRevisionViewController.php
+++ b/src/applications/differential/controller/DifferentialRevisionViewController.php
@@ -1315,7 +1315,7 @@
     }
 
     return id(new HarbormasterUnitSummaryView())
-      ->setUser($viewer)
+      ->setViewer($viewer)
       ->setExcuse($excuse)
       ->setBuildable($diff->getBuildable())
       ->setUnitMessages($diff->getUnitMessages())
diff --git a/src/applications/harbormaster/controller/HarbormasterBuildableViewController.php b/src/applications/harbormaster/controller/HarbormasterBuildableViewController.php
--- a/src/applications/harbormaster/controller/HarbormasterBuildableViewController.php
+++ b/src/applications/harbormaster/controller/HarbormasterBuildableViewController.php
@@ -318,7 +318,7 @@
 
     if ($lint_data) {
       $lint_table = id(new HarbormasterLintPropertyView())
-        ->setUser($viewer)
+        ->setViewer($viewer)
         ->setLimit(10)
         ->setLintMessages($lint_data);
 
@@ -343,6 +343,7 @@
 
     if ($unit_data) {
       $unit = id(new HarbormasterUnitSummaryView())
+        ->setViewer($viewer)
         ->setBuildable($buildable)
         ->setUnitMessages($unit_data)
         ->setShowViewAll(true)
diff --git a/src/applications/harbormaster/controller/HarbormasterUnitMessageListController.php b/src/applications/harbormaster/controller/HarbormasterUnitMessageListController.php
--- a/src/applications/harbormaster/controller/HarbormasterUnitMessageListController.php
+++ b/src/applications/harbormaster/controller/HarbormasterUnitMessageListController.php
@@ -39,6 +39,7 @@
     }
 
     $unit = id(new HarbormasterUnitSummaryView())
+      ->setViewer($viewer)
       ->setBuildable($buildable)
       ->setUnitMessages($unit_data);
 
diff --git a/src/applications/harbormaster/controller/HarbormasterUnitMessageViewController.php b/src/applications/harbormaster/controller/HarbormasterUnitMessageViewController.php
--- a/src/applications/harbormaster/controller/HarbormasterUnitMessageViewController.php
+++ b/src/applications/harbormaster/controller/HarbormasterUnitMessageViewController.php
@@ -88,23 +88,7 @@
       pht('Run At'),
       phabricator_datetime($message->getDateCreated(), $viewer));
 
-    $details = $message->getUnitMessageDetails();
-    if (strlen($details)) {
-      // TODO: Use the log view here, once it gets cleaned up.
-      // Shenanigans below.
-      $details = phutil_tag(
-        'div',
-        array(
-          'class' => 'PhabricatorMonospaced',
-          'style' =>
-            'white-space: pre-wrap; '.
-            'color: #666666; '.
-            'overflow-x: auto;',
-        ),
-        $details);
-    } else {
-      $details = phutil_tag('em', array(), pht('No details provided.'));
-    }
+    $details = $message->newUnitMessageDetailsView($viewer);
 
     $view->addSectionHeader(
       pht('Details'),
diff --git a/src/applications/harbormaster/storage/build/HarbormasterBuildUnitMessage.php b/src/applications/harbormaster/storage/build/HarbormasterBuildUnitMessage.php
--- a/src/applications/harbormaster/storage/build/HarbormasterBuildUnitMessage.php
+++ b/src/applications/harbormaster/storage/build/HarbormasterBuildUnitMessage.php
@@ -13,6 +13,9 @@
 
   private $buildTarget = self::ATTACHABLE;
 
+  const FORMAT_TEXT = 'text';
+  const FORMAT_REMARKUP = 'remarkup';
+
   public static function initializeNewUnitMessage(
     HarbormasterBuildTarget $build_target) {
     return id(new HarbormasterBuildUnitMessage())
@@ -66,6 +69,13 @@
         'description' => pht(
           'Additional human-readable information about the failure.'),
       ),
+      'format' => array(
+        'type' => 'optional string',
+        'description' => pht(
+          'Format for the text provided in "details". Valid values are '.
+          '"text" (default) or "remarkup". This controls how test details '.
+          'are rendered when shown to users.'),
+      ),
     );
   }
 
@@ -104,6 +114,11 @@
       $obj->setProperty('details', $details);
     }
 
+    $format = idx($dict, 'format');
+    if ($format) {
+      $obj->setProperty('format', $format);
+    }
+
     return $obj;
   }
 
@@ -149,6 +164,66 @@
     return $this->getProperty('details', '');
   }
 
+  public function getUnitMessageDetailsFormat() {
+    return $this->getProperty('format', self::FORMAT_TEXT);
+  }
+
+  public function newUnitMessageDetailsView(
+    PhabricatorUser $viewer,
+    $summarize = false) {
+
+    $format = $this->getUnitMessageDetailsFormat();
+
+    $is_text = ($format !== self::FORMAT_REMARKUP);
+    $is_remarkup = ($format === self::FORMAT_REMARKUP);
+
+    $full_details = $this->getUnitMessageDetails();
+
+    if (!strlen($full_details)) {
+      if ($summarize) {
+        return null;
+      }
+      $details = phutil_tag('em', array(), pht('No details provided.'));
+    } else if ($summarize) {
+      if ($is_text) {
+        $details = id(new PhutilUTF8StringTruncator())
+          ->setMaximumBytes(2048)
+          ->truncateString($full_details);
+        $details = phutil_split_lines($details);
+
+        $limit = 3;
+        if (count($details) > $limit) {
+          $details = array_slice($details, 0, $limit);
+        }
+
+        $details = implode('', $details);
+      } else {
+        $details = $full_details;
+      }
+    } else {
+      $details = $full_details;
+    }
+
+    require_celerity_resource('harbormaster-css');
+
+    $classes = array();
+    $classes[] = 'harbormaster-unit-details';
+
+    if ($is_remarkup) {
+      $details = new PHUIRemarkupView($viewer, $details);
+    } else {
+      $classes[] = 'harbormaster-unit-details-text';
+      $classes[] = 'PhabricatorMonospaced';
+    }
+
+    return phutil_tag(
+      'div',
+      array(
+        'class' => implode(' ', $classes),
+      ),
+      $details);
+  }
+
   public function getUnitMessageDisplayName() {
     $name = $this->getName();
 
diff --git a/src/applications/harbormaster/view/HarbormasterUnitPropertyView.php b/src/applications/harbormaster/view/HarbormasterUnitPropertyView.php
--- a/src/applications/harbormaster/view/HarbormasterUnitPropertyView.php
+++ b/src/applications/harbormaster/view/HarbormasterUnitPropertyView.php
@@ -34,9 +34,8 @@
     return $this;
   }
 
-
   public function render() {
-    require_celerity_resource('harbormaster-css');
+    $viewer = $this->getViewer();
 
     $messages = $this->unitMessages;
     $messages = msort($messages, 'getSortKey');
@@ -84,13 +83,10 @@
           $name);
       }
 
-      $details = $message->getUnitMessageDetails();
-      if (strlen($details)) {
-        $name = array(
-          $name,
-          $this->renderUnitTestDetails($details),
-        );
-      }
+      $name = array(
+        $name,
+        $message->newUnitMessageDetailsView($viewer, true),
+      );
 
       $rows[] = array(
         $result_icon,
@@ -158,25 +154,4 @@
     return $table;
   }
 
-  private function renderUnitTestDetails($full_details) {
-    $details = id(new PhutilUTF8StringTruncator())
-      ->setMaximumBytes(2048)
-      ->truncateString($full_details);
-    $details = phutil_split_lines($details);
-
-    $limit = 3;
-    if (count($details) > $limit) {
-      $details = array_slice($details, 0, $limit);
-    }
-
-    $details = implode('', $details);
-
-    return phutil_tag(
-      'div',
-      array(
-        'class' => 'PhabricatorMonospaced harbormaster-unit-details',
-      ),
-      $details);
-  }
-
 }
diff --git a/src/applications/harbormaster/view/HarbormasterUnitSummaryView.php b/src/applications/harbormaster/view/HarbormasterUnitSummaryView.php
--- a/src/applications/harbormaster/view/HarbormasterUnitSummaryView.php
+++ b/src/applications/harbormaster/view/HarbormasterUnitSummaryView.php
@@ -77,6 +77,7 @@
       ->setBackground(PHUIObjectBoxView::BLUE_PROPERTY);
 
     $table = id(new HarbormasterUnitPropertyView())
+      ->setViewer($this->getViewer())
       ->setUnitMessages($messages);
 
     if ($this->showViewAll) {
diff --git a/webroot/rsrc/css/application/harbormaster/harbormaster.css b/webroot/rsrc/css/application/harbormaster/harbormaster.css
--- a/webroot/rsrc/css/application/harbormaster/harbormaster.css
+++ b/webroot/rsrc/css/application/harbormaster/harbormaster.css
@@ -26,11 +26,14 @@
 .harbormaster-unit-details {
   margin: 8px 0 4px;
   overflow: hidden;
-  white-space: pre;
-  text-overflow: ellipsis;
   color: {$lightgreytext};
 }
 
+.harbormaster-unit-details-text {
+  white-space: pre-wrap;
+  text-overflow: ellipsis;
+}
+
 .harbormaster-log-view-loading {
   padding: 8px;
   text-align: center;