Keep track of failed paths in the Hydra database

I.e. don't use Nix's failed paths feature anymore. Easier to keep
everything in one place.

src/lib/Hydra/Controller/Admin.pm

@@ -45,7 +45,7 @@ sub clear_queue_non_current : Chained('admin') PathPart('clear-queue-non-current
 
 sub clearfailedcache : Chained('admin') PathPart('clear-failed-cache') Args(0) {
     my ($self, $c) = @_;
-    my $r = `nix-store --clear-failed-paths '*'`;
+    $c->model('DB::FailedPaths')->delete;
     $c->res->redirect($c->request->referer // "/");
 }
 

src/lib/Hydra/Helper/Nix.pm

@@ -465,9 +465,10 @@ sub restartBuilds($$) {
         # !!! Should do this in a trigger.
         $db->resultset('JobsetEvals')->search({ build => \@buildIds }, { join => 'buildIds' })->update({ nrsucceeded => undef });
 
-        # Clear Nix's negative failure cache.
+        # Clear the failed paths cache.
         # FIXME: Add this to the API.
-        system("nix-store", "--clear-failed-paths", @paths);
+        # FIXME: clear the dependencies?
+        $db->resultset('FailedPaths')->search({ path => [ @paths ]})->delete;
     });
 
     return scalar(@buildIds);

src/lib/Hydra/Schema/FailedPaths.pm

@@ -0,0 +1,65 @@
+use utf8;
+package Hydra::Schema::FailedPaths;
+
+# Created by DBIx::Class::Schema::Loader
+# DO NOT MODIFY THE FIRST PART OF THIS FILE
+
+=head1 NAME
+
+Hydra::Schema::FailedPaths
+
+=cut
+
+use strict;
+use warnings;
+
+use base 'DBIx::Class::Core';
+
+=head1 COMPONENTS LOADED
+
+=over 4
+
+=item * L<Hydra::Component::ToJSON>
+
+=back
+
+=cut
+
+__PACKAGE__->load_components("+Hydra::Component::ToJSON");
+
+=head1 TABLE: C<FailedPaths>
+
+=cut
+
+__PACKAGE__->table("FailedPaths");
+
+=head1 ACCESSORS
+
+=head2 path
+
+  data_type: 'text'
+  is_nullable: 0
+
+=cut
+
+__PACKAGE__->add_columns("path", { data_type => "text", is_nullable => 0 });
+
+=head1 PRIMARY KEY
+
+=over 4
+
+=item * L</path>
+
+=back
+
+=cut
+
+__PACKAGE__->set_primary_key("path");
+
+
+# Created by DBIx::Class::Schema::Loader v0.07033 @ 2015-06-10 14:48:16
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:WFgjfjH+szE6Ntcicmaflw
+
+
+# You can replace this text with custom code or comments, and it will be preserved on regeneration
+1;