From a30bf96349604442265561ba305cb24793a09c79 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Fri, 29 Aug 2025 15:26:15 -0400
Subject: [PATCH] `DerivationBuildingGoal::initialOutputs` make local variable

Also inline `assertPathValidity` in the process.
---
 .../build/derivation-building-goal.cc         | 33 ++++++++++---------
 .../store/build/derivation-building-goal.hh   | 12 ++-----
 2 files changed, 20 insertions(+), 25 deletions(-)

diff --git a/src/libstore/build/derivation-building-goal.cc b/src/libstore/build/derivation-building-goal.cc
index 95f0ee9d5..072bbfa93 100644
--- a/src/libstore/build/derivation-building-goal.cc
+++ b/src/libstore/build/derivation-building-goal.cc
@@ -417,7 +417,9 @@ Goal::Co DerivationBuildingGoal::gaveUpOnSubstitution()
 
 Goal::Co DerivationBuildingGoal::tryToBuild()
 {
-    /* Recheck at goal start. In particular, whereas before we were
+    std::map<std::string, InitialOutput> initialOutputs;
+
+    /* Recheck at this point. In particular, whereas before we were
        given this information by the downstream goal, that cannot happen
        anymore if the downstream goal only cares about one output, but
        we care about all outputs. */
@@ -440,7 +442,7 @@ Goal::Co DerivationBuildingGoal::tryToBuild()
             std::move(v),
         });
     }
-    checkPathValidity();
+    checkPathValidity(initialOutputs);
 
     auto started = [&]() {
         auto msg =
@@ -528,7 +530,7 @@ Goal::Co DerivationBuildingGoal::tryToBuild()
            omitted, but that would be less efficient.)  Note that since we
            now hold the locks on the output paths, no other process can
            build this derivation, so no further checks are necessary. */
-        auto [allValid, validOutputs] = checkPathValidity();
+        auto [allValid, validOutputs] = checkPathValidity(initialOutputs);
 
         if (buildMode != bmCheck && allValid) {
             debug("skipping build of derivation '%s', someone beat us to it", worker.store.printStorePath(drvPath));
@@ -556,7 +558,7 @@ Goal::Co DerivationBuildingGoal::tryToBuild()
         if (buildLocally) {
             useHook = false;
         } else {
-            switch (tryBuildHook()) {
+            switch (tryBuildHook(initialOutputs)) {
             case rpAccept:
                 /* Yes, it has started doing so.  Wait until we get
                    EOF from the hook. */
@@ -644,8 +646,16 @@ Goal::Co DerivationBuildingGoal::tryToBuild()
 
                We can only early return when the outputs are known a priori. For
                floating content-addressing derivations this isn't the case.
+
+               Aborts if any output is not valid or corrupt, and otherwise
+               returns a 'SingleDrvOutputs' structure containing all outputs.
              */
-            assertPathValidity();
+            [&] {
+                auto [allValid, validOutputs] = checkPathValidity(initialOutputs);
+                if (!allValid)
+                    throw Error("some outputs are unexpectedly invalid");
+                return validOutputs;
+            }();
 
         StorePathSet outputPaths;
         for (auto & [_, output] : builtOutputs)
@@ -960,7 +970,7 @@ BuildError DerivationBuildingGoal::fixupBuilderFailureErrorMessage(BuilderFailur
     return BuildError{e.status, msg};
 }
 
-HookReply DerivationBuildingGoal::tryBuildHook()
+HookReply DerivationBuildingGoal::tryBuildHook(const std::map<std::string, InitialOutput> & initialOutputs)
 {
 #ifdef _WIN32 // TODO enable build hook on Windows
     return rpDecline;
@@ -1239,7 +1249,8 @@ std::map<std::string, std::optional<StorePath>> DerivationBuildingGoal::queryPar
     return res;
 }
 
-std::pair<bool, SingleDrvOutputs> DerivationBuildingGoal::checkPathValidity()
+std::pair<bool, SingleDrvOutputs>
+DerivationBuildingGoal::checkPathValidity(std::map<std::string, InitialOutput> & initialOutputs)
 {
     if (drv->type().isImpure())
         return {false, {}};
@@ -1296,14 +1307,6 @@ std::pair<bool, SingleDrvOutputs> DerivationBuildingGoal::checkPathValidity()
     return {allValid, validOutputs};
 }
 
-SingleDrvOutputs DerivationBuildingGoal::assertPathValidity()
-{
-    auto [allValid, validOutputs] = checkPathValidity();
-    if (!allValid)
-        throw Error("some outputs are unexpectedly invalid");
-    return validOutputs;
-}
-
 Goal::Done DerivationBuildingGoal::doneSuccess(BuildResult::Status status, SingleDrvOutputs builtOutputs)
 {
     buildResult.status = status;
diff --git a/src/libstore/include/nix/store/build/derivation-building-goal.hh b/src/libstore/include/nix/store/build/derivation-building-goal.hh
index 07f9b21ae..d394eb3c9 100644
--- a/src/libstore/include/nix/store/build/derivation-building-goal.hh
+++ b/src/libstore/include/nix/store/build/derivation-building-goal.hh
@@ -55,8 +55,6 @@ private:
      */
     StorePathSet inputPaths;
 
-    std::map<std::string, InitialOutput> initialOutputs;
-
     /**
      * File descriptor for the log file.
      */
@@ -108,7 +106,7 @@ private:
     /**
      * Is the build hook willing to perform the build?
      */
-    HookReply tryBuildHook();
+    HookReply tryBuildHook(const std::map<std::string, InitialOutput> & initialOutputs);
 
     /**
      * Open a log file and a pipe to it.
@@ -142,13 +140,7 @@ private:
      * whether all outputs are valid and non-corrupt, and a
      * 'SingleDrvOutputs' structure containing the valid outputs.
      */
-    std::pair<bool, SingleDrvOutputs> checkPathValidity();
-
-    /**
-     * Aborts if any output is not valid or corrupt, and otherwise
-     * returns a 'SingleDrvOutputs' structure containing all outputs.
-     */
-    SingleDrvOutputs assertPathValidity();
+    std::pair<bool, SingleDrvOutputs> checkPathValidity(std::map<std::string, InitialOutput> & initialOutputs);
 
     /**
      * Forcibly kill the child process, if any.