diff --git a/src/repository/parser/ArcanistMercurialParser.php b/src/repository/parser/ArcanistMercurialParser.php
index 4eb10e2f..33e59c5c 100644
--- a/src/repository/parser/ArcanistMercurialParser.php
+++ b/src/repository/parser/ArcanistMercurialParser.php
@@ -1,240 +1,241 @@
 <?php
 
 /**
  * Parses output from various "hg" commands into structured data. This class
  * provides low-level APIs for reading "hg" output.
  *
  * @task  parse Parsing "hg" Output
  */
 final class ArcanistMercurialParser extends Phobject {
 
 
 /* -(  Parsing "hg" Output  )------------------------------------------------ */
 
 
   /**
    * Parse the output of "hg status". This provides detailed information, you
    * can get less detailed information with @{method:parseMercurialStatus}. In
    * particular, this will parse copy sources as per "hg status -C".
    *
    * @param string The stdout from running an "hg status" command.
    * @return dict Map of paths to status dictionaries.
    * @task parse
    */
   public static function parseMercurialStatusDetails($stdout) {
     $result = array();
 
     $stdout = trim($stdout);
     if (!strlen($stdout)) {
       return $result;
     }
 
     $last_path = null;
     $lines = explode("\n", $stdout);
     foreach ($lines as $line) {
       $flags = 0;
       if ($line[1] !== ' ') {
         throw new Exception(
           pht(
             "Unparsable Mercurial status line '%s'.",
             $line));
       }
       $code = $line[0];
       $path = substr($line, 2);
       switch ($code) {
         case 'A':
           $flags |= ArcanistRepositoryAPI::FLAG_ADDED;
           break;
         case 'R':
           $flags |= ArcanistRepositoryAPI::FLAG_DELETED;
           break;
         case 'M':
           $flags |= ArcanistRepositoryAPI::FLAG_MODIFIED;
           break;
         case 'C':
           // This is "clean" and included only for completeness, these files
           // have not been changed.
           break;
         case '!':
           $flags |= ArcanistRepositoryAPI::FLAG_MISSING;
           break;
         case '?':
           $flags |= ArcanistRepositoryAPI::FLAG_UNTRACKED;
           break;
         case 'I':
           // This is "ignored" and included only for completeness.
           break;
         case ' ':
           // This shows the source of a file move, so update the last file we
           // parsed to set its source.
           if ($last_path === null) {
             throw new Exception(
               pht(
                 "Unexpected copy source in %s, '%s'.",
                 'hg status',
                 $line));
           }
           $result[$last_path]['from'] = $path;
           continue 2;
         default:
           throw new Exception(pht("Unknown Mercurial status '%s'.", $code));
       }
 
       $result[$path] = array(
         'flags' => $flags,
         'from'  => null,
       );
       $last_path = $path;
     }
 
     return $result;
   }
 
 
   /**
    * Parse the output of "hg status". This provides only basic information, you
    * can get more detailed information by invoking
    * @{method:parseMercurialStatusDetails}.
    *
    * @param string The stdout from running an "hg status" command.
    * @return dict Map of paths to ArcanistRepositoryAPI status flags.
    * @task parse
    */
   public static function parseMercurialStatus($stdout) {
     $result = self::parseMercurialStatusDetails($stdout);
     return ipull($result, 'flags');
   }
 
 
   /**
    * Parse the output of "hg log". This also parses "hg outgoing", "hg parents",
    * and other similar commands. This assumes "--style default".
    *
    * @param string The stdout from running an "hg log" command.
    * @return list List of dictionaries with commit information.
    * @task parse
    */
   public static function parseMercurialLog($stdout) {
     $result = array();
 
     $stdout = trim($stdout);
     if (!strlen($stdout)) {
       return $result;
     }
 
     $chunks = explode("\n\n", $stdout);
     foreach ($chunks as $chunk) {
       $commit = array();
       $lines = explode("\n", $chunk);
       foreach ($lines as $line) {
         if (preg_match('/^(comparing with|searching for changes)/', $line)) {
           // These are sent to stdout when you run "hg outgoing" although the
           // format is otherwise identical to "hg log".
           continue;
         }
 
         if (preg_match('/^remote:/', $line)) {
           // This indicates remote error in "hg outgoing".
           continue;
         }
 
         list($name, $value) = explode(':', $line, 2);
         $value = trim($value);
         switch ($name) {
           case 'user':
             $commit['user'] = $value;
             break;
           case 'date':
             $commit['date'] = strtotime($value);
             break;
           case 'summary':
             $commit['summary'] = $value;
             break;
           case 'changeset':
             list($local, $rev) = explode(':', $value, 2);
             $commit['local'] = $local;
             $commit['rev'] = $rev;
             break;
           case 'parent':
             if (empty($commit['parents'])) {
               $commit['parents'] = array();
             }
             list($local, $rev) = explode(':', $value, 2);
             $commit['parents'][] = array(
               'local' => $local,
               'rev'   => $rev,
             );
             break;
           case 'branch':
             $commit['branch'] = $value;
             break;
           case 'tag':
             $commit['tag'] = $value;
             break;
           case 'bookmark':
             $commit['bookmark'] = $value;
             break;
           case 'obsolete':
-            // This is an extra field added by the "evolve" extension even
-            // if HGPLAIN=1 is set. See PHI502.
+          case 'instability':
+            // These are extra fields added by the "evolve" extension even
+            // if HGPLAIN=1 is set. See PHI502 and PHI718.
             break;
           default:
             throw new Exception(
               pht("Unknown Mercurial log field '%s'!", $name));
         }
       }
       $result[] = $commit;
     }
 
     return $result;
   }
 
 
   /**
    * Parse the output of "hg branches".
    *
    * @param string The stdout from running an "hg branches" command.
    * @return list A list of dictionaries with branch information.
    * @task parse
    */
   public static function parseMercurialBranches($stdout) {
     $stdout = rtrim($stdout, "\n");
     if (!strlen($stdout)) {
       // No branches; commonly, this occurs in a newly initialized repository.
       return array();
     }
 
     $lines = explode("\n", $stdout);
 
     $branches = array();
     foreach ($lines as $line) {
       $matches = null;
 
       // Output of "hg branches" normally looks like:
       //
       //  default                    15101:a21ccf4412d5
       //
       // ...but may also have human-readable cues like:
       //
       //  stable                     15095:ec222a29bdf0 (inactive)
       //
       // See the unit tests for more examples.
       $regexp = '/^(\S+(?:\s+\S+)*)\s+(\d+):([a-f0-9]+)(\s+\\(inactive\\))?$/';
 
       if (!preg_match($regexp, $line, $matches)) {
         throw new Exception(
           pht(
             "Failed to parse '%s' output: %s",
             'hg branches',
             $line));
       }
       $branches[$matches[1]] = array(
         'local'   => $matches[2],
         'rev'     => $matches[3],
       );
     }
 
     return $branches;
   }
 
 }