* Refactoring to support different installation sources in nix-env.

* Set the references for the user environment manifest properly.
* Don't copy the manifest (this was accidental).
* Don't store derivation paths in the manifest (maybe this should be
  made optional).  This cleans up the semantics of nix-env, which were
  weird.
* Hash on the output paths of activated components, not on derivation
  paths.  This is because we don't know the derivation path of already
  installed components anymore, and it allows the installation of
  components by store path (skipping Nix expressions entirely).
* Query options `--out-path' and `--drv-path' to show the output and
  derivation paths of components, respectively (the latter replaces
  the `--expr' query).

1 files changed, 16 insertions, 5 deletions

diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 013eba5947..da9d1e6358 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -94,6 +94,7 @@ static void processBinding(EvalState & state, Expr e, Derivation & drv,
 
     else if (matchAttrs(e, es)) {
         Expr a = queryAttr(e, "type");
+        
         if (a && evalString(state, a) == "derivation") {
             a = queryAttr(e, "drvPath");
             if (!a) throw Error("derivation name missing");
@@ -104,12 +105,22 @@ static void processBinding(EvalState & state, Expr e, Derivation & drv,
             /* !!! supports only single output path */
             Path outPath = evalPath(state, a);
 
-            StringSet ids;
-            ids.insert("out");
-            drv.inputDrvs[drvPath] = ids;
+            drv.inputDrvs[drvPath] = singleton<StringSet>("out");
+            ss.push_back(outPath);
+        }
+
+        else if (a && evalString(state, a) == "storePath") {
+
+            a = queryAttr(e, "outPath");
+            if (!a) throw Error("output path missing");
+            /* !!! supports only single output path */
+            Path outPath = evalPath(state, a);
+
+            drv.inputSrcs.insert(outPath);
             ss.push_back(outPath);
-        } else
-            throw Error("invalid derivation attribute");
+        }
+
+        else throw Error("invalid derivation attribute");
     }
 
     else if (matchPath(e, s)) {