diff --git a/scripts/check-nix-is-updated.sh b/scripts/check-nix-is-updated.sh
index a796b13..c7cb216 100755
--- a/scripts/check-nix-is-updated.sh
+++ b/scripts/check-nix-is-updated.sh
@@ -11,6 +11,6 @@ fail_stack2nix_check() {
   exit 1
 }
 
-\time ~/.local/bin/stack2nix --hackage-snapshot 2018-09-04T08:56:04Z . > $scriptDir/../stack2nix.nix
+\time /usr/bin/env stack2nix --hackage-snapshot 2018-09-04T08:56:04Z . > $scriptDir/../stack2nix.nix
 
 git diff --text --exit-code || fail_stack2nix_check
diff --git a/src/Stack2nix/External/Stack.hs b/src/Stack2nix/External/Stack.hs
index d136107..e75f612 100644
--- a/src/Stack2nix/External/Stack.hs
+++ b/src/Stack2nix/External/Stack.hs
@@ -59,12 +59,19 @@ import           System.Directory                               (canonicalizePat
 import           System.FilePath                                (makeRelative,
                                                                  (</>))
 import           Text.PrettyPrint.HughesPJClass                 (Doc)
+import           System.Environment                      (lookupEnv)
 
 data PackageRef
   = HackagePackage PackageIdentifierRevision
   | NonHackagePackage PackageIdentifier (PackageLocation FilePath)
   deriving (Eq, Show)
 
+getStackRoot :: IO String
+getStackRoot = fromMaybe defaultStackRoot <$> lookupEnv stackRootEnv
+  where
+    stackRootEnv = "S2N_STACK_ROOT"
+    defaultStackRoot = "/tmp/s2n"
+
 genNixFile :: Args -> Version -> FilePath -> Maybe String -> Maybe String -> DB.HackageDB -> PackageRef -> IO (Either Doc Derivation)
 genNixFile args ghcVersion baseDir uri argRev hackageDB pkgRef = do
   cwd <- getCurrentDirectory
@@ -143,7 +150,7 @@ runPlan :: FilePath
         -> Args
         -> IO ()
 runPlan baseDir remoteUri args@Args{..} = do
-  let stackRoot = "/tmp/s2n"
+  stackRoot <- getStackRoot
   createDirectoryIfMissing True stackRoot
   let globals = globalOpts baseDir stackRoot args
   let stackFile = baseDir </> argStackYaml
diff --git a/stack2nix.nix b/stack2nix.nix
index c6d1b2c..818896c 100644
--- a/stack2nix.nix
+++ b/stack2nix.nix
@@ -1,4 +1,4 @@
-# Generated using stack2nix 0.2.
+# Generated using stack2nix 0.2.1.
 
 { pkgs ? (import <nixpkgs> {})
 , compiler ? pkgs.haskell.packages.ghc843
@@ -11,6 +11,7 @@ let
     self: {
       array = null;
       base = null;
+      bin-package-db = null;
       binary = null;
       bytestring = null;
       containers = null;
@@ -6115,6 +6116,10 @@ inherit (pkgs.xorg) libXfixes;};
            ];
            doHaddock = false;
            doCheck = false;
+           preCheck = ''
+             export PATH="$PWD/dist/build/cabal2nix:$PATH"
+             export HOME="$TMPDIR/home"
+           '';
            homepage = "https://github.com/nixos/cabal2nix#readme";
            description = "Convert Cabal files into Nix build instructions";
            license = stdenv.lib.licenses.bsd3;
@@ -32586,7 +32591,7 @@ inherit (pkgs) libjpeg; inherit (pkgs) libpng; inherit (pkgs) zlib;};
          }:
          mkDerivation {
            pname = "stack2nix";
-           version = "0.2";
+           version = "0.2.1";
            src = ./.;
            configureFlags = [ "--ghc-option=-Werror" ];
            isLibrary = true;
@@ -39136,7 +39141,7 @@ inherit (pkgs) libjpeg; inherit (pkgs) libpng; inherit (pkgs) zlib;};
            pname = "yaml";
            version = "0.8.32";
            sha256 = "dc20f863deb4ee75395bf1f78268781db76be6209af67b70c05f6e1a09f47a31";
-           configureFlags = [ "-fsystem-libyaml" ];
+           configureFlags = [ "-f-system-libyaml" ];
            isLibrary = true;
            isExecutable = true;
            libraryHaskellDepends = [