Make --no-eval-cache a global setting

src/libexpr/eval.hh

@@ -375,6 +375,9 @@ struct EvalSettings : Config
 
     Setting<bool> traceFunctionCalls{this, false, "trace-function-calls",
         "Emit log messages for each function entry and exit at the 'vomit' log level (-vvvv)."};
+
+    Setting<bool> useEvalCache{this, true, "eval-cache",
+        "Whether to use the flake evaluation cache."};
 };
 
 extern EvalSettings evalSettings;

src/nix/app.cc

@@ -8,7 +8,7 @@ namespace nix {
 
 App Installable::toApp(EvalState & state)
 {
-    auto [cursor, attrPath] = getCursor(state, true);
+    auto [cursor, attrPath] = getCursor(state);
 
     auto type = cursor->getAttr("type")->getString();
 

src/nix/flake.cc

@@ -572,7 +572,7 @@ struct CmdFlakeInitCommon : virtual Args, EvalCommand
             Strings{templateName == "" ? "defaultTemplate" : templateName},
             Strings(attrsPathPrefixes), lockFlags);
 
-        auto [cursor, attrPath] = installable.getCursor(*evalState, true);
+        auto [cursor, attrPath] = installable.getCursor(*evalState);
 
         auto templateDir = cursor->getAttr("path")->getString();
 
@@ -782,7 +782,6 @@ struct CmdFlakeArchive : FlakeCommand, MixJSON, MixDryRun
 struct CmdFlakeShow : FlakeCommand
 {
     bool showLegacy = false;
-    bool useEvalCache = true;
 
     CmdFlakeShow()
     {
@@ -791,12 +790,6 @@ struct CmdFlakeShow : FlakeCommand
             .description = "show the contents of the 'legacyPackages' output",
             .handler = {&showLegacy, true}
         });
-
-        addFlag({
-            .longName = "no-eval-cache",
-            .description = "do not use the flake evaluation cache",
-            .handler = {[&]() { useEvalCache = false; }}
-        });
     }
 
     std::string description() override
@@ -934,7 +927,7 @@ struct CmdFlakeShow : FlakeCommand
             }
         };
 
-        auto cache = openEvalCache(*state, flake, useEvalCache);
+        auto cache = openEvalCache(*state, flake);
 
         visit(*cache->getRoot(), {}, fmt(ANSI_BOLD "%s" ANSI_NORMAL, flake->flake.lockedRef), "");
     }

src/nix/installables.cc

@@ -183,8 +183,7 @@ void completeFlakeRefWithFragment(
             auto flakeRef = parseFlakeRef(flakeRefS, absPath("."));
 
             auto evalCache = openEvalCache(*evalState,
-                std::make_shared<flake::LockedFlake>(lockFlake(*evalState, flakeRef, lockFlags)),
+                std::make_shared<flake::LockedFlake>(lockFlake(*evalState, flakeRef, lockFlags)));
-                true);
 
             auto root = evalCache->getRoot();
 
@@ -273,7 +272,7 @@ Buildable Installable::toBuildable()
 }
 
 std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
-Installable::getCursors(EvalState & state, bool useEvalCache)
+Installable::getCursors(EvalState & state)
 {
     auto evalCache =
         std::make_shared<nix::eval_cache::EvalCache>(std::nullopt, state,
@@ -282,9 +281,9 @@ Installable::getCursors(EvalState & state, bool useEvalCache)
 }
 
 std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>
-Installable::getCursor(EvalState & state, bool useEvalCache)
+Installable::getCursor(EvalState & state)
 {
-    auto cursors = getCursors(state, useEvalCache);
+    auto cursors = getCursors(state);
     if (cursors.empty())
         throw Error("cannot find flake attribute '%s'", what());
     return cursors[0];
@@ -420,12 +419,11 @@ Value * InstallableFlake::getFlakeOutputs(EvalState & state, const flake::Locked
 
 ref<eval_cache::EvalCache> openEvalCache(
     EvalState & state,
-    std::shared_ptr<flake::LockedFlake> lockedFlake,
+    std::shared_ptr<flake::LockedFlake> lockedFlake)
-    bool useEvalCache)
 {
     auto fingerprint = lockedFlake->getFingerprint();
     return make_ref<nix::eval_cache::EvalCache>(
-        useEvalCache && evalSettings.pureEval
+        evalSettings.useEvalCache && evalSettings.pureEval
             ? std::optional { std::cref(fingerprint) }
             : std::nullopt,
         state,
@@ -460,10 +458,9 @@ static std::string showAttrPaths(const std::vector<std::string> & paths)
 
 std::tuple<std::string, FlakeRef, InstallableValue::DerivationInfo> InstallableFlake::toDerivation()
 {
-
     auto lockedFlake = getLockedFlake();
 
-    auto cache = openEvalCache(*state, lockedFlake, true);
+    auto cache = openEvalCache(*state, lockedFlake);
     auto root = cache->getRoot();
 
     for (auto & attrPath : getActualAttrPaths()) {
@@ -517,11 +514,10 @@ std::pair<Value *, Pos> InstallableFlake::toValue(EvalState & state)
 }
 
 std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
-InstallableFlake::getCursors(EvalState & state, bool useEvalCache)
+InstallableFlake::getCursors(EvalState & state)
 {
     auto evalCache = openEvalCache(state,
-        std::make_shared<flake::LockedFlake>(lockFlake(state, flakeRef, lockFlags)),
+        std::make_shared<flake::LockedFlake>(lockFlake(state, flakeRef, lockFlags)));
-        useEvalCache);
 
     auto root = evalCache->getRoot();
 

src/nix/installables.hh

@@ -62,10 +62,10 @@ struct Installable
     }
 
     virtual std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
-    getCursors(EvalState & state, bool useEvalCache);
+    getCursors(EvalState & state);
 
     std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>
-    getCursor(EvalState & state, bool useEvalCache);
+    getCursor(EvalState & state);
 
     virtual FlakeRef nixpkgsFlakeRef() const
     {
@@ -118,7 +118,7 @@ struct InstallableFlake : InstallableValue
     std::pair<Value *, Pos> toValue(EvalState & state) override;
 
     std::vector<std::pair<std::shared_ptr<eval_cache::AttrCursor>, std::string>>
-    getCursors(EvalState & state, bool useEvalCache) override;
+    getCursors(EvalState & state) override;
 
     std::shared_ptr<flake::LockedFlake> getLockedFlake() const;
 
@@ -127,7 +127,6 @@ struct InstallableFlake : InstallableValue
 
 ref<eval_cache::EvalCache> openEvalCache(
     EvalState & state,
-    std::shared_ptr<flake::LockedFlake> lockedFlake,
+    std::shared_ptr<flake::LockedFlake> lockedFlake);
-    bool useEvalCache);
 
 }

src/nix/search.cc

@@ -177,7 +177,7 @@ struct CmdSearch : InstallableCommand, MixJSON
             }
         };
 
-        for (auto & [cursor, prefix] : installable->getCursors(*state, true))
+        for (auto & [cursor, prefix] : installable->getCursors(*state))
             visit(*cursor, parseAttrPath(*state, prefix));
 
         if (!json && !results)