From 7d3dde851aee25808440d46faad4a2c93f167f0a Mon Sep 17 00:00:00 2001
From: eldritch horrors <pennae@lix.systems>
Date: Wed, 28 Jan 2026 12:41:26 +0100
Subject: [PATCH] libstore: make runPasta a function of
 LinuxLocalDerivationGoal

this way we can use it anywhere without fear of it being uninitialized.
only the linux platform bit uses this anyway, so we will move it there.

Change-Id: I35e207eec91daa8aa327c4f8b36c0dc8e703a7c4
---
 lix/libstore/build/local-derivation-goal.hh |  6 ------
 lix/libstore/platform/linux.cc              | 10 +++-------
 lix/libstore/platform/linux.hh              | 15 +++++++++++++++
 3 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/lix/libstore/build/local-derivation-goal.hh b/lix/libstore/build/local-derivation-goal.hh
index 6dc22651c..7c25c2727 100644
--- a/lix/libstore/build/local-derivation-goal.hh
+++ b/lix/libstore/build/local-derivation-goal.hh
@@ -278,12 +278,6 @@ struct LocalDerivationGoal : public DerivationGoal
 protected:
     using DerivationGoal::DerivationGoal;
 
-    /**
-     * Whether to run pasta for network-endowed derivations. Running pasta
-     * currently requires actively waiting for its net-ns setup to finish.
-     */
-    bool runPasta = false;
-
     /**
      * Setup dependencies outside the sandbox.
      * Called in the parent nix process.
diff --git a/lix/libstore/platform/linux.cc b/lix/libstore/platform/linux.cc
index aa6966e3d..e8398b130 100644
--- a/lix/libstore/platform/linux.cc
+++ b/lix/libstore/platform/linux.cc
@@ -904,7 +904,7 @@ void LinuxLocalDerivationGoal::prepareSandbox()
 
 std::string LinuxLocalDerivationGoal::rewriteResolvConf(std::string fromHost)
 {
-    if (!runPasta) {
+    if (!runPasta()) {
         return fromHost;
     }
 
@@ -1211,7 +1211,7 @@ bool LinuxLocalDerivationGoal::prepareChildSetup()
         throw SysError("setuid failed");
     }
 
-    if (runPasta) {
+    if (runPasta()) {
         // wait for the pasta interface to appear. pasta can't signal us when
         // it's done setting up the namespace, so we have to wait for a while
         AutoCloseFD fd(socket(PF_INET, SOCK_DGRAM, IPPROTO_IP));
@@ -1299,10 +1299,6 @@ Pid LinuxLocalDerivationGoal::startChild(
        us.
     */
 
-    // don't launch pasta unless we have a tun device. in a build sandbox we
-    // commonly do not, and trying to run pasta anyway naturally won't work.
-    runPasta = !privateNetwork() && settings.pastaPath != "" && pathExists("/dev/net/tun");
-
     userNamespaceSync.create();
 
     Pipe sendPid;
@@ -1408,7 +1404,7 @@ Pid LinuxLocalDerivationGoal::startChild(
     /* Signal the builder that we've updated its user namespace. */
     writeFull(userNamespaceSync.writeSide.get(), "1");
 
-    if (runPasta) {
+    if (runPasta()) {
         // Bring up pasta, for handling FOD networking. We don't let it daemonize
         // itself for process managements reasons and kill it manually when done.
 
diff --git a/lix/libstore/platform/linux.hh b/lix/libstore/platform/linux.hh
index 8976a7a8d..4f60f6ce4 100644
--- a/lix/libstore/platform/linux.hh
+++ b/lix/libstore/platform/linux.hh
@@ -109,5 +109,20 @@ private:
     {
         return derivationType.value().isSandboxed();
     }
+
+    /**
+     * Whether to run pasta for network-endowed derivations. Running pasta
+     * currently requires actively waiting for its net-ns setup to finish.
+     */
+    bool runPasta()
+    {
+        if (!_runPasta) {
+            // don't launch pasta unless we have a tun device. in a build sandbox we
+            // commonly do not, and trying to run pasta anyway naturally won't work.
+            _runPasta = !privateNetwork() && settings.pastaPath != "" && pathExists("/dev/net/tun");
+        }
+        return *_runPasta;
+    }
+    std::optional<bool> _runPasta;
 };
 }