* Only non-garbage collected builds can be added to a release.

src/lib/Hydra/Controller/Build.pm

@@ -372,6 +372,10 @@ sub add_to_release : Chained('build') PathPart('add-to-release') Args(0) {
 
     error($c, "This build is already a part of release `$releaseName'.")
         if $release->releasemembers->find({build => $build->id});
+ 
+    registerRoot $build->outpath;
+    
+    error($c, "This build is no longer available.") unless isValidPath $build->outpath;
 
     $release->releasemembers->create({build => $build->id, description => $build->description});
     

src/root/build.tt

@@ -206,7 +206,7 @@
 </table>
 
 
-[% IF c.user_exists %]
+[% IF c.user_exists && available %]
 <form action="[% c.uri_for('/build' build.id 'add-to-release') %]" method="post">
   <p>Add to release: <input type="text" class="string" name="name" />
   <button type="submit"><img src="/static/images/success.gif" />Apply</button></p>