diff --git a/pkgs/applications/version-management/darcs/darcs-2.nix b/pkgs/applications/version-management/darcs/darcs-2.nix
index c0efa78553b6..dd54bfa112b5 100644
--- a/pkgs/applications/version-management/darcs/darcs-2.nix
+++ b/pkgs/applications/version-management/darcs/darcs-2.nix
@@ -1,17 +1,16 @@
-{cabal, html, mtl, parsec, regexCompat, zlib, curl} :
+{cabal, html, mtl, parsec, regexCompat, curl, haskeline, hashedStorage} :
 
 cabal.mkDerivation (self : {
   pname = "darcs";
   name = self.fname;
-  version = "2.2.1";
-  sha256 = "0iy4d4qls6yhwmgv87pz4kmr5jh4bwigz1wfwzns71b68csynnsp";
+  version = "2.3.1";
+  sha256 = "14821bb2db4975cb4db2c5cc4f085069b936da591b7b71592befc9e07f17d214";
 
-  extraBuildInputs = [html mtl parsec regexCompat zlib curl];
+  extraBuildInputs = [html parsec regexCompat curl haskeline hashedStorage];
 
   meta = {
     homepage = http://darcs.net/;
     description = "Patch-based version management system";
   };
 
-  patches = ./bash-completion.patch; # I didn't have "have"
 })
diff --git a/pkgs/development/libraries/haskell/hashed-storage/default.nix b/pkgs/development/libraries/haskell/hashed-storage/default.nix
new file mode 100644
index 000000000000..de1893697727
--- /dev/null
+++ b/pkgs/development/libraries/haskell/hashed-storage/default.nix
@@ -0,0 +1,12 @@
+{cabal, mtl, zlib, mmap}:
+
+cabal.mkDerivation (self : {
+  pname = "hashed-storage";
+  version = "0.3.8";
+  sha256 = "1f379dcb00a56c0b330eeabb1f069ef294bcf1f3dc18980e93b8b228e577fdb1";
+  propagatedBuildInputs = [mtl zlib mmap];
+  meta = {
+    description = "Hashed file storage support code";
+  };
+})  
+
diff --git a/pkgs/development/libraries/haskell/mmap/default.nix b/pkgs/development/libraries/haskell/mmap/default.nix
new file mode 100644
index 000000000000..66324ba80833
--- /dev/null
+++ b/pkgs/development/libraries/haskell/mmap/default.nix
@@ -0,0 +1,11 @@
+{cabal}:
+
+cabal.mkDerivation (self : {
+  pname = "mmap";
+  version = "0.4.1";
+  sha256 = "792b8ecfb0cce1f8588f0d2a63c6893ff98a2479c06745583da8166d5a46ead9";
+  meta = {
+    description = "Memory mapped files for POSIX and Windows";
+  };
+})  
+
diff --git a/pkgs/top-level/haskell-packages.nix b/pkgs/top-level/haskell-packages.nix
index b9a846d097f9..30d684ddf687 100644
--- a/pkgs/top-level/haskell-packages.nix
+++ b/pkgs/top-level/haskell-packages.nix
@@ -175,6 +175,10 @@ rec {
     inherit cabal HaXml mtl network stm hslogger HAppSUtil HAppSData bytestring binary hspread;
   };
 
+  hashedStorage = import ../development/libraries/haskell/hashed-storage {
+    inherit cabal mtl zlib mmap;
+  };
+
   haskeline = import ../development/libraries/haskell/haskeline {
     inherit cabal extensibleExceptions mtl utf8String;
   };
@@ -285,6 +289,10 @@ rec {
     inherit cabal benchpress;
   };
 
+  mmap = import ../development/libraries/haskell/mmap {
+    inherit cabal;
+  };
+
   monadlab = import ../development/libraries/haskell/monadlab {
     inherit cabal parsec;
   };
@@ -641,8 +649,8 @@ rec {
   # Applications.
 
   darcs = import ../applications/version-management/darcs/darcs-2.nix {
-    inherit cabal html mtl parsec regexCompat;
-    inherit (pkgs) zlib curl;
+    inherit cabal html mtl parsec regexCompat haskeline hashedStorage;
+    inherit (pkgs) curl;
   };
 
   leksah = import ../applications/editors/leksah {