diff --git a/lix/libstore/build/local-derivation-goal.cc b/lix/libstore/build/local-derivation-goal.cc
index 159657e79..078920a33 100644
--- a/lix/libstore/build/local-derivation-goal.cc
+++ b/lix/libstore/build/local-derivation-goal.cc
@@ -860,8 +860,23 @@ try {
         setupConfiguredCertificateAuthority();
     }
 
+    /* Fill in the environment. */
+    Strings envStrs;
+    for (auto & i : env) {
+        envStrs.push_back(rewriteStrings(i.first + "=" + i.second, inputRewrites));
+    }
+
+    /* Fill in the arguments. */
+    Strings args;
+
+    args.push_back(std::string(baseNameOf(drv->builder)));
+
+    for (auto & i : drv->args) {
+        args.push_back(rewriteStrings(i, inputRewrites));
+    }
+
     /* Fork a child to build the package. */
-    pid = startChild(netrcData, caFileData, std::move(builderOut));
+    pid = startChild(netrcData, caFileData, envStrs, args, std::move(builderOut));
 
     /* parent */
     pid.setSeparatePG(true);
@@ -900,6 +915,8 @@ try {
 Pid LocalDerivationGoal::startChild(
     const std::optional<std::string> & netrcData,
     const std::optional<std::string> & caFileData,
+    const Strings & envStrs,
+    const Strings & args,
     AutoCloseFD logPTY
 )
 {
@@ -908,7 +925,7 @@ Pid LocalDerivationGoal::startChild(
             throw SysError("failed to redirect build output to log file");
         }
         closeOnExec(STDERR_FILENO, false);
-        runChild(netrcData, caFileData);
+        runChild(netrcData, caFileData, envStrs, args);
     });
 }
 
@@ -1144,7 +1161,10 @@ void LocalDerivationGoal::chownToBuilder(const AutoCloseFD & fd)
 }
 
 void LocalDerivationGoal::runChild(
-    const std::optional<std::string> & netrcData, const std::optional<std::string> & caFileData
+    const std::optional<std::string> & netrcData,
+    const std::optional<std::string> & caFileData,
+    const Strings & envStrs,
+    const Strings & args
 )
 {
     /* Warning: in the child we should absolutely not make any SQLite
@@ -1174,11 +1194,6 @@ void LocalDerivationGoal::runChild(
 
         // FIXME: set other limits to deterministic values?
 
-        /* Fill in the environment. */
-        Strings envStrs;
-        for (auto & i : env)
-            envStrs.push_back(rewriteStrings(i.first + "=" + i.second, inputRewrites));
-
         /* If we are running in `build-users' mode, then switch to the
            user we allocated above.  Make sure that we drop all root
            privileges.  Note that above we have closed all file
@@ -1205,14 +1220,6 @@ void LocalDerivationGoal::runChild(
 
         finishChildSetup();
 
-        /* Fill in the arguments. */
-        Strings args;
-
-        args.push_back(std::string(baseNameOf(drv->builder)));
-
-        for (auto & i : drv->args)
-            args.push_back(rewriteStrings(i, inputRewrites));
-
         /* Indicate that we managed to set up the build environment. */
         writeFull(STDERR_FILENO, std::string("\2\n"));
 
diff --git a/lix/libstore/build/local-derivation-goal.hh b/lix/libstore/build/local-derivation-goal.hh
index 870122306..31fc2d3a2 100644
--- a/lix/libstore/build/local-derivation-goal.hh
+++ b/lix/libstore/build/local-derivation-goal.hh
@@ -214,8 +214,12 @@ struct LocalDerivationGoal : public DerivationGoal
     /**
      * Run the builder's process.
      */
-    void
-    runChild(const std::optional<std::string> & netrcData, const std::optional<std::string> & caFileData);
+    void runChild(
+        const std::optional<std::string> & netrcData,
+        const std::optional<std::string> & caFileData,
+        const Strings & envStrs,
+        const Strings & args
+    );
 
     /**
      * Check that the derivation outputs all exist and register them
@@ -315,6 +319,8 @@ protected:
     virtual Pid startChild(
         const std::optional<std::string> & netrcData,
         const std::optional<std::string> & caFileData,
+        const Strings & envStrs,
+        const Strings & args,
         AutoCloseFD logPTY
     );
 
diff --git a/lix/libstore/platform/linux.cc b/lix/libstore/platform/linux.cc
index c6c94ed63..50cf9d295 100644
--- a/lix/libstore/platform/linux.cc
+++ b/lix/libstore/platform/linux.cc
@@ -1241,6 +1241,8 @@ bool LinuxLocalDerivationGoal::prepareChildSetup()
 Pid LinuxLocalDerivationGoal::startChild(
     const std::optional<std::string> & netrcData,
     const std::optional<std::string> & caFileData,
+    const Strings & envStrs,
+    const Strings & args,
     AutoCloseFD logPTY
 )
 {
@@ -1253,7 +1255,7 @@ Pid LinuxLocalDerivationGoal::startChild(
 
     // If we're not sandboxing no need to faff about, use the fallback
     if (!useChroot) {
-        return LocalDerivationGoal::startChild(netrcData, caFileData, std::move(logPTY));
+        return LocalDerivationGoal::startChild(netrcData, caFileData, envStrs, args, std::move(logPTY));
     }
     /* Set up private namespaces for the build:
 
@@ -1329,7 +1331,8 @@ Pid LinuxLocalDerivationGoal::startChild(
             options.cloneFlags |= CLONE_NEWUSER;
         }
 
-        pid_t child = startProcess([&]() { runChild(netrcData, caFileData); }, options).release();
+        pid_t child =
+            startProcess([&]() { runChild(netrcData, caFileData, envStrs, args); }, options).release();
 
         writeFull(sendPid.writeSide.get(), fmt("%d\n", child));
         _exit(0);
diff --git a/lix/libstore/platform/linux.hh b/lix/libstore/platform/linux.hh
index 4f6c92a75..29e44315c 100644
--- a/lix/libstore/platform/linux.hh
+++ b/lix/libstore/platform/linux.hh
@@ -76,6 +76,8 @@ private:
     Pid startChild(
         const std::optional<std::string> & netrcData,
         const std::optional<std::string> & caFileData,
+        const Strings & envStrs,
+        const Strings & args,
         AutoCloseFD logPTY
     ) override;