don't exit optimize early so we record cache keys

pkg/executor/build.go

@@ -141,7 +141,7 @@ func (s *stageBuilder) optimize(compositeKey CompositeCache, cfg v1.Config) erro
  layerCache := &cache.RegistryCache{
  Opts: s.opts,
  }
-
+ stopCache := false
  // Possibly replace commands with their cached implementations.
  // We walk through all the commands, running any commands that only operate on metadata.
  // We throw the metadata away after, but we need it to properly track command dependencies
@@ -167,13 +167,14 @@ func (s *stageBuilder) optimize(compositeKey CompositeCache, cfg v1.Config) erro
  return err
  }
  s.finalCacheKey = ck
- if command.ShouldCacheOutput() {
+ if command.ShouldCacheOutput() && !stopCache {
  img, err := layerCache.RetrieveLayer(ck)
  if err != nil {
  logrus.Debugf("Failed to retrieve layer: %s", err)
  logrus.Infof("No cached layer found for cmd %s", command.String())
  logrus.Debugf("Key missing was: %s", compositeKey.Key())
- break
+ stopCache = true
+ continue
  }
 
  if cacheCmd := command.CacheCommand(img); cacheCmd != nil {