Merge pull request #9648 from cole-h/nix-shell-ordering

nix shell: reflect command line order in PATH order

(cherry picked from commit b91c935c2faf08ced2c763dcd2a831f26d84fa86)
Change-Id: If16c120bb74857c2817366e74e5b0877eb997260

src/libcmd/installables.cc

@@ -674,7 +674,7 @@ BuiltPaths Installable::toBuiltPaths(
     }
 }
 
-StorePathSet Installable::toStorePaths(
+StorePathSet Installable::toStorePathSet(
     ref<Store> evalStore,
     ref<Store> store,
     Realise mode, OperateOn operateOn,
@@ -688,13 +688,27 @@ StorePathSet Installable::toStorePaths(
     return outPaths;
 }
 
+StorePaths Installable::toStorePaths(
+    ref<Store> evalStore,
+    ref<Store> store,
+    Realise mode, OperateOn operateOn,
+    const Installables & installables)
+{
+    StorePaths outPaths;
+    for (auto & path : toBuiltPaths(evalStore, store, mode, operateOn, installables)) {
+        auto thisOutPaths = path.outPaths();
+        outPaths.insert(outPaths.end(), thisOutPaths.begin(), thisOutPaths.end());
+    }
+    return outPaths;
+}
+
 StorePath Installable::toStorePath(
     ref<Store> evalStore,
     ref<Store> store,
     Realise mode, OperateOn operateOn,
     ref<Installable> installable)
 {
-    auto paths = toStorePaths(evalStore, store, mode, operateOn, {installable});
+    auto paths = toStorePathSet(evalStore, store, mode, operateOn, {installable});
 
     if (paths.size() != 1)
         throw Error("argument '%s' should evaluate to one store path", installable->what());

src/libcmd/installables.hh

@@ -166,7 +166,14 @@ struct Installable
         const Installables & installables,
         BuildMode bMode = bmNormal);
 
-    static std::set<StorePath> toStorePaths(
+    static std::set<StorePath> toStorePathSet(
+        ref<Store> evalStore,
+        ref<Store> store,
+        Realise mode,
+        OperateOn operateOn,
+        const Installables & installables);
+
+    static std::vector<StorePath> toStorePaths(
         ref<Store> evalStore,
         ref<Store> store,
         Realise mode,

src/nix/develop.cc

@@ -340,7 +340,7 @@ struct Common : InstallableCommand, MixProfile
         for (auto & [installable_, dir_] : redirects) {
             auto dir = absPath(dir_);
             auto installable = parseInstallable(store, installable_);
-            auto builtPaths = Installable::toStorePaths(
+            auto builtPaths = Installable::toStorePathSet(
                 getEvalStore(), store, Realise::Nothing, OperateOn::Output, {installable});
             for (auto & path: builtPaths) {
                 auto from = store->printStorePath(path);
@@ -554,7 +554,7 @@ struct CmdDevelop : Common, MixEnvironment
 
             bool found = false;
 
-            for (auto & path : Installable::toStorePaths(getEvalStore(), store, Realise::Outputs, OperateOn::Output, {bashInstallable})) {
+            for (auto & path : Installable::toStorePathSet(getEvalStore(), store, Realise::Outputs, OperateOn::Output, {bashInstallable})) {
                 auto s = store->printStorePath(path) + "/bin/bash";
                 if (pathExists(s)) {
                     shell = s;

src/nix/run.cc

@@ -113,7 +113,7 @@ struct CmdShell : InstallablesCommand, MixEnvironment
 
         setEnviron();
 
-        auto unixPath = tokenizeString<Strings>(getEnv("PATH").value_or(""), ":");
+        std::vector<std::string> pathAdditions;
 
         while (!todo.empty()) {
             auto path = todo.front();
@@ -121,7 +121,7 @@ struct CmdShell : InstallablesCommand, MixEnvironment
             if (!done.insert(path).second) continue;
 
             if (true)
-                unixPath.push_front(store->printStorePath(path) + "/bin");
+                pathAdditions.push_back(store->printStorePath(path) + "/bin");
 
             auto propPath = store->printStorePath(path) + "/nix-support/propagated-user-env-packages";
             if (accessor->stat(propPath).type == FSAccessor::tRegular) {
@@ -130,7 +130,10 @@ struct CmdShell : InstallablesCommand, MixEnvironment
             }
         }
 
-        setenv("PATH", concatStringsSep(":", unixPath).c_str(), 1);
+        auto unixPath = tokenizeString<Strings>(getEnv("PATH").value_or(""), ":");
+        unixPath.insert(unixPath.begin(), pathAdditions.begin(), pathAdditions.end());
+        auto unixPathString = concatStringsSep(":", unixPath);
+        setenv("PATH", unixPathString.c_str(), 1);
 
         Strings args;
         for (auto & arg : command) args.push_back(arg);