Added flags to override the lockfile

.gitignore

@@ -84,6 +84,7 @@ perl/Makefile.config
 /tests/restricted-innocent
 /tests/shell
 /tests/shell.drv
+/tests/config.nix
 
 # /tests/lang/
 /tests/lang/*.out

src/libexpr/common-eval-args.cc

@@ -3,6 +3,7 @@
 #include "download.hh"
 #include "util.hh"
 #include "eval.hh"
+#include "flake/flakeref.hh"
 
 namespace nix {
 
@@ -33,15 +34,6 @@ MixEvalArgs::MixEvalArgs()
         .handler([&](std::vector<std::string> ss) {
             evalSettings.pureEval = false;
         });
-
-    mkFlag()
-      .longName("override-flake")
-      .labels({"original-ref", "resolved-ref"})
-      .description("override a flake registry value")
-      .arity(2)
-      .handler([&](std::vector<std::string> ss) {
-          registryOverrides.push_back(std::make_pair(ss[0], ss[1]));
-      });
 }
 
 Bindings * MixEvalArgs::getAutoArgs(EvalState & state)

src/libexpr/common-eval-args.hh

@@ -16,8 +16,6 @@ struct MixEvalArgs : virtual Args
 
     Strings searchPath;
 
-    std::vector<std::pair<std::string, std::string>> registryOverrides;
-
 private:
 
     std::map<std::string, std::string> autoArgs;

src/libexpr/eval.hh

@@ -6,6 +6,7 @@
 #include "symbol-table.hh"
 #include "hash.hh"
 #include "config.hh"
+#include "flake/flakeref.hh"
 
 #include <map>
 #include <unordered_map>
@@ -66,7 +67,7 @@ typedef std::list<SearchPathElem> SearchPath;
 /* Initialise the Boehm GC, if applicable. */
 void initGC();
 
-typedef std::vector<std::pair<std::string, std::string>> RegistryOverrides;
+typedef std::map<FlakeRef, FlakeRef> RegistryOverrides;
 
 
 class EvalState
@@ -96,6 +97,8 @@ public:
 
     RegistryOverrides registryOverrides;
 
+    RegistryOverrides lockFileOverrides;
+
 
 private:
     SrcToStore srcToStore;
@@ -221,6 +224,8 @@ public:
 
     void addRegistryOverrides(RegistryOverrides overrides) { registryOverrides = overrides; }
 
+    void addLockFileOverrides(RegistryOverrides overrides) { lockFileOverrides = overrides; }
+
 public:
 
     /* The base environment, containing the builtin functions and

src/libexpr/flake/flake.cc

@@ -64,9 +64,7 @@ std::shared_ptr<FlakeRegistry> getUserRegistry()
 std::shared_ptr<FlakeRegistry> getFlagRegistry(RegistryOverrides registryOverrides)
 {
     auto flagRegistry = std::make_shared<FlakeRegistry>();
-    for (auto const & x : registryOverrides) {
-        flagRegistry->entries.insert_or_assign(FlakeRef(x.first), FlakeRef(x.second));
-    }
+    flagRegistry->entries = registryOverrides;
     return flagRegistry;
 }
 
@@ -339,8 +337,15 @@ static std::pair<Flake, FlakeInput> updateLocks(
     for (auto & input : flake.nonFlakeInputs) {
         auto & id = input.first;
         auto & ref = input.second;
+        auto j = state.lockFileOverrides.find(FlakeRef(id)); // The LockFile can be overrides by flags.
         auto i = oldEntry.nonFlakeInputs.find(id);
-        if (i != oldEntry.nonFlakeInputs.end()) {
+        if (j != state.lockFileOverrides.end()) {
+            auto nonFlake = getNonFlake(state, j->second, allowedToUseRegistries(handleLockFile, false));
+            newEntry.nonFlakeInputs.insert_or_assign(id,
+                NonFlakeInput(
+                    nonFlake.sourceInfo.resolvedRef,
+                    nonFlake.sourceInfo.narHash));
+        } else if (i != oldEntry.nonFlakeInputs.end()) {
             newEntry.nonFlakeInputs.insert_or_assign(i->first, i->second);
         } else {
             if (handleLockFile == AllPure || handleLockFile == TopRefUsesRegistries)
@@ -354,8 +359,15 @@ static std::pair<Flake, FlakeInput> updateLocks(
     }
 
     for (auto & inputRef : flake.inputs) {
+        auto j = state.lockFileOverrides.find(inputRef); // The LockFile can be overrides by flags.
         auto i = oldEntry.flakeInputs.find(inputRef);
-        if (i != oldEntry.flakeInputs.end()) {
+        if (j != state.lockFileOverrides.end()) {
+            auto flake = getFlake(state, j->first, allowedToUseRegistries(handleLockFile, false));
+            newEntry.flakeInputs.insert_or_assign(inputRef,
+                updateLocks(state,
+                    getFlake(state, j->second, allowedToUseRegistries(handleLockFile, false)),
+                    handleLockFile, {}, false).second);
+        } else if (i != oldEntry.flakeInputs.end()) {
             newEntry.flakeInputs.insert_or_assign(inputRef, i->second);
         } else {
             if (handleLockFile == AllPure || handleLockFile == TopRefUsesRegistries)

src/nix/build.cc

@@ -48,8 +48,8 @@ struct CmdBuild : MixDryRun, InstallablesCommand
     {
         auto buildables = build(store, dryRun ? DryRun : Build, installables);
 
-        auto evalState = std::make_shared<EvalState>(searchPath, store);
-        evalState->addRegistryOverrides(registryOverrides);
+        auto evalState = getEvalState();
+
         if (dryRun) return;
 
         for (size_t i = 0; i < buildables.size(); ++i) {

src/nix/command.hh

@@ -3,6 +3,7 @@
 #include "args.hh"
 #include "common-eval-args.hh"
 #include <optional>
+#include "flake/flakeref.hh"
 
 namespace nix {
 
@@ -70,6 +71,12 @@ struct EvalCommand : virtual StoreCommand, MixEvalArgs
 {
     ref<EvalState> getEvalState();
 
+    std::map<FlakeRef, FlakeRef> registryOverrides;
+
+    std::map<FlakeRef, FlakeRef> lockFileOverrides;
+
+    EvalCommand();
+
 private:
 
     std::shared_ptr<EvalState> evalState;

src/nix/flake.cc

@@ -136,7 +136,6 @@ struct CmdFlakeDeps : FlakeCommand
     void run(nix::ref<nix::Store> store) override
     {
         auto evalState = getEvalState();
-        evalState->addRegistryOverrides(registryOverrides);
 
         std::queue<ResolvedFlake> todo;
         todo.push(resolveFlake());

src/nix/installables.cc

@@ -58,9 +58,32 @@ ref<EvalState> EvalCommand::getEvalState()
 {
     if (!evalState)
         evalState = std::make_shared<EvalState>(searchPath, getStore());
+    evalState->addRegistryOverrides(registryOverrides);
+    evalState->addLockFileOverrides(lockFileOverrides);
     return ref<EvalState>(evalState);
 }
 
+EvalCommand::EvalCommand()
+{
+    mkFlag()
+      .longName("override-flake")
+      .labels({"original-ref", "resolved-ref"})
+      .description("override a flake registry value")
+      .arity(2)
+      .handler([&](std::vector<std::string> ss) {
+          registryOverrides.insert_or_assign(FlakeRef(ss[0]), FlakeRef(ss[1]));
+      });
+
+    mkFlag()
+      .longName("override-lock")
+      .labels({"original-ref", "resolved-ref"})
+      .description("override a lockfile value")
+      .arity(2)
+      .handler([&](std::vector<std::string> ss) {
+          lockFileOverrides.insert_or_assign(FlakeRef(ss[0]), FlakeRef(ss[1]));
+      });
+}
+
 Buildable Installable::toBuildable()
 {
     auto buildables = toBuildables();

tests/flakes.sh

@@ -328,3 +328,8 @@ git -C $flake3Dir checkout master
 # Test whether fuzzy-matching works for IsGit
 (! nix build -o $TEST_ROOT/result --flake-registry $registry flake4/removeXyzzy:xyzzy)
 nix build -o $TEST_ROOT/result --flake-registry $registry flake4/removeXyzzy:sth
+
+# Test overide-lockfile
+nix build -o $TEST_ROOT/result --flake-registry $registry flake4:xyzzy --override-lock flake3 flake3/removeXyzzy
+# Test that the flake registry is entirely used
+[[ -z $(nix build -o $TEST_ROOT/result --flake-registry $registry flake3:xyzzy --override-lock flake2 flake1) ]]