* Fork of build-env in the Nix distribution. This one supports

ignoring collisions and selectively including directories.

svn path=/nixpkgs/trunk/; revision=7160

pkgs/build-support/buildenv/default.nix

@@ -0,0 +1,29 @@
+# buildEnv creates a tree of symlinks to the specified paths.  This is
+# a fork of the buildEnv in the Nix distribution.  Most changes should
+# eventually be merged back into the Nix distribution.
+
+{stdenv, perl}:
+
+{ name
+
+, # The manifest file (if any).  A symlink $out/manifest will be
+  # created to it.
+  manifest ? ""
+  
+, # The paths to symlink.
+  paths
+  
+, # Whether to ignore collisions or abort.
+  ignoreCollisions ? false
+
+, # The paths (relative to each element of `paths') that we want to
+  # symlink (e.g., ["/bin"]).  Any file not inside any of the
+  # directories in the list is not symlinked.
+  pathsToLink ? ["/"]
+}:
+
+stdenv.mkDerivation {
+  inherit name manifest paths ignoreCollisions pathsToLink;
+  realBuilder = perl + "/bin/perl";
+  args = ["-w" ./builder.pl];
+}