diff --git a/src/core/codec.rs b/src/core/codec.rs
index 3ac6fdd72..274b8400e 100644
--- a/src/core/codec.rs
+++ b/src/core/codec.rs
@@ -40,10 +40,6 @@ impl SegmentSerializer {
         &mut self.fast_field_serializer
     }
 
-    pub fn segment(&self,) -> Segment {
-        self.segment.clone()
-    }
-
     pub fn store_doc(&mut self, field_values_it: &mut Iterator<Item=&TextFieldValue>) -> io::Result<()> {
         let field_values: Vec<&TextFieldValue> = field_values_it.collect();
         try!(self.store_writer.store(&field_values));
diff --git a/src/core/fstmap.rs b/src/core/fstmap.rs
index 40477194f..f7b9c1ed3 100644
--- a/src/core/fstmap.rs
+++ b/src/core/fstmap.rs
@@ -72,9 +72,6 @@ pub struct FstMapIter<'a, V: 'static + BinarySerializable> {
 }
 
 impl<'a, V: 'static + BinarySerializable> FstMapIter<'a, V> {
-
-    // type Item = (Vec<u8>, V);
-
     pub fn next(&mut self) -> Option<(&[u8], V)> {
         let next_item = self.streamer.next();
         match next_item {
diff --git a/src/core/merger.rs b/src/core/merger.rs
index 8cab38ef2..04dca5a23 100644
--- a/src/core/merger.rs
+++ b/src/core/merger.rs
@@ -163,7 +163,7 @@ impl IndexMerger {
                 max_val = max(max_val, u32_reader.max_val());
                 u32_readers.push((reader.max_doc(), u32_reader));
             }
-            fast_field_serializer.new_u32_fast_field(field, min_val, max_val);
+            try!(fast_field_serializer.new_u32_fast_field(field, min_val, max_val));
             for (max_doc, u32_reader) in u32_readers {
                 for doc_id in 0..max_doc {
                     let val = u32_reader.get(doc_id);
@@ -206,7 +206,6 @@ mod tests {
     use core::index::Index;
     use core::schema::Term;
     use core::collector::TestCollector;
-    use super::IndexMerger;
 
     #[test]
     fn test_index_merger() {
@@ -234,7 +233,7 @@ mod tests {
                     doc.set(&text_field, "a b c d");
                     index_writer.add_document(doc).unwrap();
                 }
-                index_writer.wait();
+                index_writer.wait().unwrap();
             }
 
             {
@@ -250,7 +249,7 @@ mod tests {
                     doc.set(&text_field, "a b c g");
                     index_writer.add_document(doc).unwrap();
                 }
-                index_writer.wait();
+                index_writer.wait().unwrap();
             }
         }
         {
diff --git a/src/lib.rs b/src/lib.rs
index 6408e3e33..d65477f0f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -89,7 +89,7 @@ mod tests {
         let mut schema = schema::Schema::new();
         let text_fieldtype = schema::TextOptions::new().set_tokenized_indexed();
         let text_field = schema.add_text_field("text", &text_fieldtype);
-        let index = Index::create_from_tempdir(schema).unwrap();
+        let index = Index::create_in_ram(schema);
 
         {
             // writing the segment
@@ -110,7 +110,7 @@ mod tests {
                 index_writer.add_document(doc).unwrap();
             }
             //let commit_result = index_writer.commit();
-            index_writer.wait();
+            index_writer.wait().unwrap();
             //commit_result.unwrap();
         }
         {