@@ -37,6 +37,7 @@ import (

 	digest "github.com/opencontainers/go-digest"

 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"

 	"github.com/pkg/errors"

+	"github.com/sirupsen/logrus"

 )

 // Opt defines a structure for creating a worker.

@@ -77,32 +78,33 @@ func NewWorker(opt Opt) (*Worker, error) {

 		CacheAccessor: cm,

 		MetadataStore: opt.MetadataStore,

 	})

-	if err != nil {

-		return nil, err

+	if err == nil {

+		sm.Register(gs)

+	} else {

+		logrus.Warnf("Could not register builder git source: %s", err)

 	}

-	sm.Register(gs)

-

 	hs, err := http.NewSource(http.Opt{

 		CacheAccessor: cm,

 		MetadataStore: opt.MetadataStore,

 		Transport:     opt.Transport,

 	})

-	if err != nil {

-		return nil, err

+	if err == nil {

+		sm.Register(hs)

+	} else {

+		logrus.Warnf("Could not register builder http source: %s", err)

 	}

-	sm.Register(hs)

-

 	ss, err := local.NewSource(local.Opt{

 		SessionManager: opt.SessionManager,

 		CacheAccessor:  cm,

 		MetadataStore:  opt.MetadataStore,

 	})

-	if err != nil {

-		return nil, err

+	if err == nil {

+		sm.Register(ss)

+	} else {

+		logrus.Warnf("Could not register builder local source: %s", err)

 	}

-	sm.Register(ss)

 	return &Worker{

 		Opt:           opt,