diff --git a/audacity.cabal b/audacity.cabal
--- a/audacity.cabal
+++ b/audacity.cabal
@@ -1,5 +1,5 @@
 Name:                audacity
-Version:             0.0.2.2
+Version:             0.0.2.3
 Synopsis:            Interchange with the Audacity sound signal editor
 Description:
   This package provides functions
@@ -41,7 +41,7 @@
 Cabal-Version:       >=1.10
 
 Source-Repository this
-  Tag:         0.0.2.2
+  Tag:         0.0.2.3
   Type:        darcs
   Location:    https://hub.darcs.net/thielema/audacity
 
@@ -75,9 +75,9 @@
     non-empty >=0.2.1 && <0.4,
     utility-ht >=0.0.10 && <0.1,
     explicit-exception >=0.1.7 && <0.3,
-    semigroups >=0.1 && <1.0,
+    semigroups >=0.1 && <1,
     transformers >=0.3 && <0.7,
-    deepseq >=1.3 && <1.6,
+    deepseq >=1.3 && <1.7,
     base >=4.5 && <5
   Hs-Source-Dirs:      src
   Default-Language:    Haskell2010
@@ -95,7 +95,7 @@
       soxlib >=0.0 && <0.1,
       storablevector,
       directory,
-      optparse-applicative >=0.11 && <0.19,
+      optparse-applicative >=0.11 && <0.20,
       filepath >=1.3 && <1.6,
       non-empty,
       utility-ht,
@@ -115,7 +115,7 @@
       soxlib >=0.0 && <0.1,
       storablevector,
       directory,
-      optparse-applicative >=0.11 && <0.19,
+      optparse-applicative >=0.11 && <0.20,
       filepath >=1.3 && <1.6,
       non-empty,
       utility-ht,
@@ -135,7 +135,7 @@
       soxlib >=0.0 && <0.1,
       storablevector,
       directory,
-      optparse-applicative >=0.11 && <0.19,
+      optparse-applicative >=0.11 && <0.20,
       filepath >=1.3 && <1.6,
       non-empty,
       utility-ht,
@@ -155,7 +155,7 @@
       soxlib >=0.0 && <0.1,
       storablevector,
       directory,
-      optparse-applicative >=0.11 && <0.19,
+      optparse-applicative >=0.11 && <0.20,
       filepath >=1.3 && <1.6,
       non-empty,
       utility-ht,
diff --git a/src/Sound/Audacity/LabelTrack.hs b/src/Sound/Audacity/LabelTrack.hs
--- a/src/Sound/Audacity/LabelTrack.hs
+++ b/src/Sound/Audacity/LabelTrack.hs
@@ -114,6 +114,14 @@
    lift $
       filter (uncurry (<) . fst) .
       map (mapFst (mapPair (max from, min to)))
+{-
+mask :: (time, time) -> T time label
+mask (from,to) =
+   lift $ mapMaybe $ \((fromi,toi), label) ->
+      let fromTrim = max from fromi
+          toTrim   = min to toi
+      in  toMaybe (fromTrim < toTrim) ((fromTrim, toTrim), label)
+-}
 
 
 zipWithList ::
diff --git a/src/Sound/Audacity/Project/Track/Label.hs b/src/Sound/Audacity/Project/Track/Label.hs
--- a/src/Sound/Audacity/Project/Track/Label.hs
+++ b/src/Sound/Audacity/Project/Track/Label.hs
@@ -79,6 +79,7 @@
    MM.MaybeT (ME.Exceptional Parser.Message) a ->
    Maybe (ME.Exceptional Parser.Message a)
 maybeExc (MM.MaybeT act) =
+   -- Trav.sequence act
    case act of
       ME.Exception msg -> Just $ ME.Exception msg
       ME.Success ma -> fmap ME.Success ma