Remove this dependency.

digit.cabal

@@ -12,7 +12,6 @@ library
   build-depends:       base
                      , QuickCheck
                      , lens
-                     , missing-lens
                      , regex-applicative
                      , text
   default-language:    Haskell2010

src/Data/Digit.hs

@@ -23,7 +23,6 @@ module Data.Digit
   ) where
 
 import Control.Lens
-import Control.Lens.Missing
 import Data.Foldable as F
 import Data.List as L
 import Data.List.NonEmpty as NE
@@ -117,6 +116,7 @@ _Digits = below _Digit
 
 _DigitsText :: Prism' Text (NE.NonEmpty Digit)
 _DigitsText = from packed . _Digits . _NonEmptyList
+  where _NonEmptyList = prism' NE.toList NE.nonEmpty
 
 _DigitsInt :: Integral n => Prism' n NormalDigits
 _DigitsInt = prism' (digitsToNum . unDigits) positiveIntToDigits

stack.yaml

@@ -1,8 +1,4 @@
-resolver: lts-19.0
+resolver: lts-20.3
 
 packages:
 - .
-
-extra-deps:
-- git: https://github.com/typeable/missing-lens.git
-  commit: 328659fdda8fd7ec509abfab6298775062fc2926