* updated darcs to 1.0.5, added curl dependency

* added an experimental fetchdarcs function, based on fetchsvn
  (there are no expressions yet that use this function)

svn path=/nixpkgs/trunk/; revision=4615

pkgs/build-support/fetchdarcs/builder.sh

@@ -0,0 +1,22 @@
+source $stdenv/setup
+
+tagtext=""
+tagflags=""
+if test -n "$tag"; then
+    tagtext="(tag $tag) "
+    tagflags="--tag=$tag"
+fi
+
+header "getting $url ${tagtext}into $out"
+
+darcs get --no-pristine-tree $tagflags "$url" "$out"
+# remove metadata, because it can change
+rm -rf "$out/_darcs"
+
+actual=$(nix-hash $out)
+if test "$actual" != "$outputHash"; then
+    echo "hash is $actual, expected $outputHash" >&2
+    exit 1
+fi
+
+stopNest

pkgs/build-support/fetchdarcs/default.nix

@@ -0,0 +1,16 @@
+{stdenv, darcs, nix}: {url, tag ? null, md5}:
+
+stdenv.mkDerivation {
+  name = "fetchdarcs";
+  builder = ./builder.sh;
+  buildInputs = [darcs nix];
+
+  # Nix <= 0.7 compatibility.
+  id = md5;
+
+  outputHashAlgo = "md5";
+  outputHashMode = "recursive";
+  outputHash = md5;
+  
+  inherit url tag;
+}