Works kinda

Estinien.cabal

@@ -50,12 +50,14 @@ extra-doc-files:    CHANGELOG.md
 -- Extra source files to be distributed with the package, such as examples, or a tutorial module.
 -- extra-source-files:
 
-common warnings
+common default
     ghc-options: -Wall
+                 -threaded
+                 -rtsopts
 
 library
     -- Import common warning flags.
-    import:           warnings
+    import:           default
 
     -- Modules exported by the library.
     exposed-modules:  Sudoku
@@ -71,6 +73,7 @@ library
                     , matrix
                     , vector
                     , parallel
+                    , deepseq
 
     -- Directories containing source files.
     hs-source-dirs:   src
@@ -80,7 +83,7 @@ library
 
 executable Estinien
     -- Import common warning flags.
-    import:           warnings
+    import:           default
 
     -- .hs or .lhs file containing the Main module.
     main-is:          Main.hs