* Option to show the tail of a log.

src/lib/Hydra/Controller/Build.pm

@@ -65,7 +65,7 @@ sub showLog {
 
     notFound($c, "Log file $path no longer exists.") unless -f $path;
 
-    if ($mode eq "") {
+    if (!$mode) {
         # !!! quick hack
         my $pipeline = ($path =~ /.bz2$/ ? "cat $path | bzip2 -d" : "cat $path")
             . " | nix-log2xml | xsltproc " . $c->path_to("xsl/mark-errors.xsl") . " -"
@@ -79,6 +79,11 @@ sub showLog {
         $c->serve_static_file($path);
     }
 
+    elsif ($mode eq "tail") {
+        $c->stash->{'plain'} = { data => scalar `tail -n 50 $path` };
+        $c->forward('Hydra::View::Plain');
+    }
+
     else {
         error($c, "Unknown log display mode `$mode'.");
     }

src/lib/Hydra/View/Plain.pm

@@ -0,0 +1,7 @@
+package Hydra::View::Plain;
+
+use strict;
+use warnings;
+use base 'Catalyst::View::Download::Plain';
+
+1;

src/root/build.tt

@@ -163,7 +163,8 @@
         <th>Logfile:</th>
         <td>
           <a href="[% c.uri_for('/build' build.id 'log') %]"><strong>Available</strong></a>
-          (<a href="[% c.uri_for('/build' build.id 'log' 'raw') %]">raw</a>)
+          (<a href="[% c.uri_for('/build' build.id 'log' 'raw') %]">raw</a>,
+           <a href="[% c.uri_for('/build' build.id 'log' 'tail') %]">tail</a>)
         </td>
       </tr>
     [% END %]
@@ -274,7 +275,7 @@
             <span class="error">Failed: [% HTML.escape(step.errormsg) %]</span>
           [% END %]
           [% IF step.logfile %]
-            (<a href="[% log %]">log</a>, <a href="[% "$log/raw" %]">raw</a>)
+            (<a href="[% log %]">log</a>, <a href="[% "$log/raw" %]">raw</a>, <a href="[% "$log/tail" %]">tail</a>)
           [% END %]
         </td>
       </tr>

src/script/hydra_scheduler.pl

@@ -368,7 +368,7 @@ sub checkJobSet {
     # Store the errors messages for jobs that failed to evaluate.
     my $msg = "";
     foreach my $error (@{$jobs->{error}}) {
-        $msg .= "at `" . $error->{location} . "': " . $error->{msg} . "\n";
+        $msg .= "at `" . $error->{location} . "': " . $error->{msg} . "\n\n";
     }
     setJobsetError($jobset, $msg);
 }