Implement build salvage routines

If a new build of a dist that"s already in the db fails (e.g. due to network errors), we need to catch that and update the Build ID in the database for that dist, so that it does not get purged as a removed dist at the end of the build process.

lib/ModulesPerl6/DbBuilder/Dist.pm

@@ -43,11 +43,14 @@ sub _load_from_source {
     for my $source ( $self->_sources ) {
         next unless $url =~ $source->re;
         log info => "Using $source to load $url";
-        my $dist = $source->new(
+        my $dist_source = $source->new(
             meta_url  => $url,
             logos_dir => $self->_logos_dir,
             dist_db   => $self->_dist_db,
-        )->load or return;
+        )
+        my $dist = $dist_source->load
+            return $self->_salvage_build( $dist_source );
+
         $dist->{build_id} = $self->_build_id;
 
         for my $postprocessor ( $self->_postprocessors ) {
@@ -67,4 +70,14 @@ sub _load_from_source {
     return;
 }
 
+sub _salvage_build {
+    my ( $self, $dist_source ) = @_;
+
+    my $dist = $dist_source->_dist;
+    $self->_dist_db->salvage_build( $dist->{url}, $self->_build_id )
+        if ref $dist and length $dist->{url};
+
+    return;
+}
+
 1;

lib/ModulesPerl6/Model/Dists.pm

@@ -111,6 +111,16 @@ sub remove_old {
     $num_deleted;
 }
 
+sub salvage_build {
+    my ( $self, $url, $new_build_id ) = @_;
+    return unless length $url and length $new_build_id;
+
+    $self->_db->resultset('Dist')->search({ url => $url })
+        ->update_all({ build_id => $new_build_id });
+
+    return 1;
+}
+
 1;
 
 __END__