use HydraFrontend::Helper::Nix;

    return error($c, "Not yet implemented.");

    return error($c, "Product is not a Nix build.") if $product->type ne "nix-build";
    return error($c, "Path " . $product->path . " is no longer available.") unless HydraFrontend::Helper::Nix::isValidPath($product->path);
    $c->stash->{current_view} = 'HydraFrontend::View::NixClosure';
    $c->stash->{storePath} = $product->path;
    $c->stash->{name} = $build->nixname;

package HydraFrontend::Helper::Nix;
use strict;
sub isValidPath {
    my $path = shift;
    $SIG{CHLD} = 'DEFAULT'; # !!! work around system() failing if SIGCHLD is ignored
    return system("nix-store --check-validity $path") == 0;
}
1;

package HydraFrontend::View::NixClosure;
use strict;
use base qw/Catalyst::View/;
use IO::Pipe;
use POSIX qw(dup2);
sub process {
    my ( $self, $c ) = @_;
    
    $c->response->content_type('application/x-nix-export');
    $c->response->header('Content-Disposition' => 'attachment; filename=' . $c->stash->{name} . '.closure.gz');
    my $storePath = $c->stash->{storePath};
    open(OUTPUT, "nix-store --export `nix-store -qR $storePath` | gzip |");
    my $fh = new IO::Handle;
    $fh->fdopen(fileno(OUTPUT), "r") or die;
    $c->response->body($fh);
    
    return 1;
}
1;

__PACKAGE__->config( name => 'HydraFrontend' );

__PACKAGE__->config(
    name => 'HydraFrontend',
    default_view => "TT"
    );

[% USE HTML %]

      [<a class="productDetailsToggle" href="javascript:">help</a>]
      <div class="help productDetails">
        <p>If you have Nix installed on your machine, this build and all
        its dependencies can be unpacked into your local Nix store by
        doing:</p>
        
        <pre>$ gunzip < [% HTML.escape(build.nixname) %].closure.gz | nix-store --import</pre>
        or to download and unpack in one command:
        <pre>$ curl [% c.uri_for('/closure' build.id product.productnr) %] | gunzip | nix-store --import</pre>
        
        <p>The package can then be found in the path <tt>[%
        product.path %]</tt>.  If you get the error message “imported
        archive lacks a signature”, you should make sure that you have
        sufficient access rights to the Nix store, e.g., run the
        command as <tt>root</tt>.</p>
      </div>

div.help {
    border: solid black 1px;
    padding-left: 1em;
    padding-right: 1em;
}

div.help pre {
    padding-left: 1.5em;
    color: #400000;
}