Merge "Print chained exceptions when maintenance script fails."

diff --cc maintenance/doMaintenance.php
index 94ae95d,816b385..0ee1e6a
--- 1/maintenance/doMaintenance.php
--- 2/maintenance/doMaintenance.php
+++ b/maintenance/doMaintenance.php
@@@ -92,10 -90,18 +92,20 @@@ $maintenance->checkRequiredExtensions()
  // This avoids having long running scripts just OOM and lose all the updates.
  $maintenance->setAgentAndTriggers();
  
 +$maintenance->validateParamsAndArgs();
 +
  // Do the work
- $success = $maintenance->execute();
+ try {
+       $success = $maintenance->execute();
+ } catch ( Exception $ex ) {
+       $success = false;
+       while ( $ex ) {
+               $cls = get_class( $ex );
+               print "$cls from line {$ex->getLine()} of {$ex->getFile()}: {$ex->getMessage()}\n";
+               print $ex->getTraceAsString() . "\n";
+               $ex = $ex->getPrevious();
+       }
+ }
  
  // Potentially debug globals
  $maintenance->globals();