improving log messages

index/store/forestdb/reader.go

@@ -12,6 +12,8 @@
 package forestdb
 
 import (
+	"fmt"
+
 	"github.com/blevesearch/bleve/index/store"
 	"github.com/couchbaselabs/goforestdb"
 )
@@ -24,7 +26,7 @@ type Reader struct {
 func newReader(store *Store) (*Reader, error) {
 	snapshot, err := store.newSnapshot()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error opening snapshot: %v", err)
 	}
 	return &Reader{
 		store:    store,

index/store/forestdb/store.go

@@ -159,7 +159,7 @@ func (s *Store) getSeqNum() (forestdb.SeqNum, error) {
 func (s *Store) newSnapshot() (*forestdb.KVStore, error) {
 	seqNum, err := s.getSeqNum()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error getting snapshot seqnum %v", err)
 	}
 	return s.dbkv.SnapshotOpen(seqNum)
 }

index/upside_down/upside_down.go

@@ -12,6 +12,7 @@ package upside_down
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
 	"math"
 	"sync/atomic"
 	"time"
@@ -631,7 +632,7 @@ func (udc *UpsideDownCouch) DeleteInternal(key []byte) error {
 func (udc *UpsideDownCouch) Reader() (index.IndexReader, error) {
 	kvr, err := udc.store.Reader()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error opening store reader: %v", err)
 	}
 	return &IndexReader{
 		index:    udc,

index_impl.go

@@ -368,7 +368,7 @@ func (i *indexImpl) Search(req *SearchRequest) (*SearchResult, error) {
 	// open a reader for this search
 	indexReader, err := i.i.Reader()
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error opening index reader %v", err)
 	}
 	defer indexReader.Close()