* It is now possible to add store derivations or paths directly to a

  user environment, e.g.,

    $ nix-env -i /nix/store/z58v41v21xd3ywrqk1vmvdwlagjx7f10-aterm-2.3.1.drv

  or 

    $ nix-env -i /nix/store/hsyj5pbn0d9iz7q0aj0fga7cpaadvp1l-aterm-2.3.1

  This is useful because it allows Nix expressions to be bypassed
  entirely.  For instance, if only a nix-pull manifest is provided,
  plus the top-level path of some component, it can be installed
  without having to supply the Nix expression (e.g., for obfuscation,
  or to be independent of Nix expression language changes or context
  dependencies).

4 files changed, 52 insertions, 10 deletions

diff --git a/src/libstore/build.hh b/src/libstore/build.hh
index 2c6bcf9f2d..45997ebb24 100644
--- a/src/libstore/build.hh
+++ b/src/libstore/build.hh
@@ -28,4 +28,9 @@ Derivation derivationFromPath(const Path & drvPath);
 void computeFSClosure(const Path & storePath,
     PathSet & paths, bool flipDirection = false);
 
+/* Return the path corresponding to the output identifier `id' in the
+   given derivation. */
+Path findOutput(const Derivation & drv, string id);
+    
+
 #endif /* !__BUILD_H */
diff --git a/src/libstore/misc.cc b/src/libstore/misc.cc
index 5f20ee2775..f3cc98bf4e 100644
--- a/src/libstore/misc.cc
+++ b/src/libstore/misc.cc
@@ -27,3 +27,12 @@ void computeFSClosure(const Path & storePath,
          i != references.end(); ++i)
         computeFSClosure(*i, paths, flipDirection);
 }
+
+
+ Path findOutput(const Derivation & drv, string id)
+{
+    for (DerivationOutputs::const_iterator i = drv.outputs.begin();
+         i != drv.outputs.end(); ++i)
+        if (i->first == id) return i->second.path;
+    throw Error(format("derivation has no output `%1%'") % id);
+}
diff --git a/src/nix-env/main.cc b/src/nix-env/main.cc
index a250413ab1..bab1f7fe14 100644
--- a/src/nix-env/main.cc
+++ b/src/nix-env/main.cc
@@ -2,6 +2,7 @@
 #include "names.hh"
 #include "globals.hh"
 #include "build.hh"
+#include "gc.hh"
 #include "shared.hh"
 #include "parser.hh"
 #include "eval.hh"
@@ -226,6 +227,12 @@ static void createUserEnv(EvalState & state, const UserEnvElems & elems,
             ));
         manifest = ATinsert(manifest, t);
         inputs = ATinsert(inputs, makeStr(toATerm(i->second.outPath)));
+
+        /* This is only necessary when installing store paths, e.g.,
+           `nix-env -i /nix/store/abcd...-foo'. */
+        addTempRoot(i->second.outPath);
+        ensurePath(i->second.outPath);
+        
         references.insert(i->second.outPath);
         if (drvPath != "") references.insert(drvPath);
     }
@@ -270,7 +277,11 @@ static void queryInstSources(EvalState & state,
     const InstallSourceInfo & instSource, const Strings & args,
     UserEnvElems & elems)
 {
-    switch (instSource.type) {
+    InstallSourceType type = instSource.type;
+    if (type == srcUnknown && args.size() > 0 && args.front()[0] == '/')
+        type = srcStorePaths;
+    
+    switch (type) {
 
         /* Get the available user environment elements from the
            derivations specified in a Nix expression, including only
@@ -333,6 +344,32 @@ static void queryInstSources(EvalState & state,
             break;
 
         case srcStorePaths:
+
+            for (Strings::const_iterator i = args.begin();
+                 i != args.end(); ++i)
+            {
+                assertStorePath(*i);
+
+                UserEnvElem elem;
+                string name = baseNameOf(*i);
+                unsigned int dash = name.find('-');
+                if (dash != string::npos)
+                    name = string(name, dash + 1);
+
+                if (isDerivation(*i)) {
+                    elem.drvPath = *i;
+                    elem.outPath = findOutput(derivationFromPath(*i), "out");
+                    if (name.size() >= drvExtension.size() &&
+                        string(name, name.size() - drvExtension.size()) == drvExtension)
+                        name = string(name, 0, name.size() - drvExtension.size());
+                }
+                else elem.outPath = *i;
+
+                elem.name = name;
+
+                elems[elem.outPath] = elem;
+            }
+            
             break;
 
         case srcProfile:
diff --git a/src/nix-store/main.cc b/src/nix-store/main.cc
index fa7960c382..a93956ab7a 100644
--- a/src/nix-store/main.cc
+++ b/src/nix-store/main.cc
@@ -23,15 +23,6 @@ static int rootNr = 0;
 static bool indirectRoot = false;
 
 
-static Path findOutput(const Derivation & drv, string id)
-{
-    for (DerivationOutputs::const_iterator i = drv.outputs.begin();
-         i != drv.outputs.end(); ++i)
-        if (i->first == id) return i->second.path;
-    throw Error(format("derivation has no output `%1%'") % id);
-}
-
-
 static Path fixPath(Path path)
 {
     path = absPath(path);