diff --git a/lix/legacy/builtin-builder.cc b/lix/legacy/builtin-builder.cc
index 78f10055c..8132439c0 100644
--- a/lix/legacy/builtin-builder.cc
+++ b/lix/legacy/builtin-builder.cc
@@ -34,6 +34,12 @@ static int main_builtin_builder(AsyncIoRoot & aio, std::string programName, Stri
         return *argvIt++;
     };
 
+    if (auto val = string2Int<int>(getArg("verbosity"))) {
+        verbosity = verbosityFromIntClamped(*val);
+    } else {
+        throw Error("expected a verbosity argument");
+    }
+
     while (argvIt != argvEnd) {
         const auto arg = getArg("option");
         if (arg == "--") {
@@ -41,7 +47,8 @@ static int main_builtin_builder(AsyncIoRoot & aio, std::string programName, Stri
         } else if (!arg.starts_with("--")) {
             throw Error("unexpected builtin option %s", arg);
         }
-        settings.set(arg.substr(2), unescapeNul(getArg(arg)));
+        auto value = unescapeNul(getArg(arg));
+        globalConfig.set(arg.substr(2), value);
     }
 
     while (argvIt != argvEnd) {
diff --git a/lix/libstore/build/local-derivation-goal.cc b/lix/libstore/build/local-derivation-goal.cc
index 57b679ae5..38b287c19 100644
--- a/lix/libstore/build/local-derivation-goal.cc
+++ b/lix/libstore/build/local-derivation-goal.cc
@@ -872,9 +872,13 @@ try {
 
     if (drv->isBuiltin()) {
         args.push_back("builtin-builder");
+        args.push_back(std::to_string(verbosity));
 
-        std::map<std::string, AbstractConfig::SettingInfo> overriddenSettings;
-        settings.getSettings(overriddenSettings, true);
+        std::map<std::string, AbstractConfig::SettingInfo> changedSettings;
+        globalConfig.getChangedSettings(changedSettings);
+
+        // we won't need them since we're launching *into* a sandbox, and the list is quite large
+        changedSettings.erase(settings.builtinBuilderSandboxPaths.name);
 
         /* Make the contents of netrc and the CA certificate bundle
            available to builtin:fetchurl (which may run under a
@@ -888,7 +892,7 @@ try {
                 }
 
                 if (!data.empty()) {
-                    overriddenSettings[thing.name].value = tmpDirInSandbox + "/" + thing.name;
+                    changedSettings[thing.name].value = tmpDirInSandbox + "/" + thing.name;
                     auto path = tmpDir + "/" + thing.name;
                     writeFile(path, data, 0600);
                     chownToBuilder(path);
@@ -899,7 +903,7 @@ try {
             expose(settings.caFile);
         }
 
-        for (const auto & [setting, value] : overriddenSettings) {
+        for (const auto & [setting, value] : changedSettings) {
             args.push_back("--" + setting);
             args.push_back(escapeNul(value.value));
         }