n starts + qual

src/lib.rs

@@ -136,7 +136,7 @@ pub fn range_depths(
         let rstart = pileup.pos() as i32;
         if rstart >= start && rstart < stop {
             // depths.push(pileup.depth());
-            let v = depths.get_mut((rstart - start) as usize).unwrap();
+            let v = depths.get_mut((rstart - start) as usize).context(format!("Errrr {}", rstart - start))?;
             *v = pileup.depth();
         } else if rstart >= stop {
             break;