* Allow the output/expression id to be forced to a certain

  value; this potentially dangerous feature enables better 
  sharing for those paths for which the content is known in 
  advance (e.g., because a content hash is given).
* Fast builds: if we can expand all output paths of a derive 
  expression, we don't have to build.

1 files changed, 1 insertions, 0 deletions

diff --git a/corepkgs/fetchurl/fetchurl.fix b/corepkgs/fetchurl/fetchurl.fix
index f798c0becbc2..0221b612cfe3 100644
--- a/corepkgs/fetchurl/fetchurl.fix
+++ b/corepkgs/fetchurl/fetchurl.fix
@@ -4,6 +4,7 @@ Function(["url", "md5"],
     , ("url", Var("url"))
     , ("md5", Var("md5"))
     , ("name", BaseName(Var("url")))
+    , ("id", Var("md5"))
     ]
   )
 )