Allow setting the state directory as a store parameter

E.g. "local?store=/tmp/store&state=/tmp/var".

2 files changed, 18 insertions, 11 deletions

diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc
index fbb0f61a1..3f0486bb6 100644
--- a/src/nix-env/nix-env.cc
+++ b/src/nix-env/nix-env.cc
@@ -692,6 +692,9 @@ static void opSetFlag(Globals & globals, Strings opFlags, Strings opArgs)
 
 static void opSet(Globals & globals, Strings opFlags, Strings opArgs)
 {
+    auto store2 = globals.state->store.dynamic_pointer_cast<LocalFSStore>();
+    if (!store2) throw Error("--set is not supported for this Nix store");
+
     for (Strings::iterator i = opFlags.begin(); i != opFlags.end(); ) {
         string arg = *i++;
         if (parseInstallSourceOptions(globals, i, opFlags, arg)) ;
@@ -722,7 +725,7 @@ static void opSet(Globals & globals, Strings opFlags, Strings opArgs)
     }
 
     debug(format("switching to new user environment"));
-    Path generation = createGeneration(globals.state->store, globals.profile, drv.queryOutPath());
+    Path generation = createGeneration(ref<LocalFSStore>(store2), globals.profile, drv.queryOutPath());
     switchLink(globals.profile, generation);
 }
 
diff --git a/src/nix-env/user-env.cc b/src/nix-env/user-env.cc
index ca27a7248..f239f6377 100644
--- a/src/nix-env/user-env.cc
+++ b/src/nix-env/user-env.cc
@@ -131,18 +131,22 @@ bool createUserEnv(EvalState & state, DrvInfos & elems,
     state.store->buildPaths({topLevelDrv}, state.repair ? bmRepair : bmNormal);
 
     /* Switch the current user environment to the output path. */
-    PathLocks lock;
-    lockProfile(lock, profile);
+    auto store2 = state.store.dynamic_pointer_cast<LocalFSStore>();
 
-    Path lockTokenCur = optimisticLockProfile(profile);
-    if (lockToken != lockTokenCur) {
-        printMsg(lvlError, format("profile ‘%1%’ changed while we were busy; restarting") % profile);
-        return false;
-    }
+    if (store2) {
+        PathLocks lock;
+        lockProfile(lock, profile);
+
+        Path lockTokenCur = optimisticLockProfile(profile);
+        if (lockToken != lockTokenCur) {
+            printMsg(lvlError, format("profile ‘%1%’ changed while we were busy; restarting") % profile);
+            return false;
+        }
 
-    debug(format("switching to new user environment"));
-    Path generation = createGeneration(state.store, profile, topLevelOut);
-    switchLink(profile, generation);
+        debug(format("switching to new user environment"));
+        Path generation = createGeneration(ref<LocalFSStore>(store2), profile, topLevelOut);
+        switchLink(profile, generation);
+    }
 
     return true;
 }