* Add nix version to footer of hydra pages

src/lib/Hydra/Controller/Root.pm

@@ -15,6 +15,7 @@ sub begin :Private {
     my ($self, $c) = @_;
     $c->stash->{curUri} = $c->request->uri;
     $c->stash->{version} = $ENV{"HYDRA_RELEASE"} || "<devel>";
+    $c->stash->{nixVersion} = $ENV{"NIX_RELEASE"} || "<devel>";
 }
 
 

src/root/layout.tt

@@ -80,7 +80,7 @@
         [% content %]
         <div id="footer">
           <hr />
-          <em>Hydra [% HTML.escape(version) %].</em>
+          <em>Hydra [% HTML.escape(version) %] (using [% HTML.escape(nixVersion) %]).</em>
           Page generated on [% INCLUDE renderDateTime %].
           [% IF c.user_exists %]
           You are logged in as <tt>[% c.user.username %]</tt>.