From b0c016ae7d1b04f5bd89ccd54b3698bb3d76d38b Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Mon, 24 Nov 2025 15:03:46 -0500
Subject: [PATCH] `DummyStore` build trace holds `UnkeyedRealisation` by value

Otherwise the equality instance we need to add will be messed up.
---
 src/libstore-tests/dummy-store.cc                  | 2 +-
 src/libstore/dummy-store.cc                        | 7 +++----
 src/libstore/include/nix/store/dummy-store-impl.hh | 2 +-
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/libstore-tests/dummy-store.cc b/src/libstore-tests/dummy-store.cc
index 3dd8137a3..c87b8d773 100644
--- a/src/libstore-tests/dummy-store.cc
+++ b/src/libstore-tests/dummy-store.cc
@@ -27,7 +27,7 @@ TEST(DummyStore, realisation_read)
         .outPath = StorePath{"g1w7hy3qg1w7hy3qg1w7hy3qg1w7hy3q-foo.drv"},
     };
 
-    store->buildTrace.insert({drvHash, {{outputName, make_ref<UnkeyedRealisation>(value)}}});
+    store->buildTrace.insert({drvHash, {{outputName, value}}});
 
     auto value2 = store->queryRealisation({drvHash, outputName});
 
diff --git a/src/libstore/dummy-store.cc b/src/libstore/dummy-store.cc
index c45a13cc3..57bbcd231 100644
--- a/src/libstore/dummy-store.cc
+++ b/src/libstore/dummy-store.cc
@@ -320,9 +320,8 @@ struct DummyStoreImpl : DummyStore
 
     void registerDrvOutput(const Realisation & output) override
     {
-        auto ref = make_ref<UnkeyedRealisation>(output);
-        buildTrace.insert_or_visit({output.id.drvHash, {{output.id.outputName, ref}}}, [&](auto & kv) {
-            kv.second.insert_or_assign(output.id.outputName, make_ref<UnkeyedRealisation>(output));
+        buildTrace.insert_or_visit({output.id.drvHash, {{output.id.outputName, output}}}, [&](auto & kv) {
+            kv.second.insert_or_assign(output.id.outputName, output);
         });
     }
 
@@ -333,7 +332,7 @@ struct DummyStoreImpl : DummyStore
         buildTrace.cvisit(drvOutput.drvHash, [&](const auto & kv) {
             if (auto it = kv.second.find(drvOutput.outputName); it != kv.second.end()) {
                 visited = true;
-                callback(it->second.get_ptr());
+                callback(std::make_shared<UnkeyedRealisation>(it->second));
             }
         });
 
diff --git a/src/libstore/include/nix/store/dummy-store-impl.hh b/src/libstore/include/nix/store/dummy-store-impl.hh
index 137f81c9b..095767aaf 100644
--- a/src/libstore/include/nix/store/dummy-store-impl.hh
+++ b/src/libstore/include/nix/store/dummy-store-impl.hh
@@ -47,7 +47,7 @@ struct DummyStore : virtual Store
      * outer map for the derivation, and inner maps for the outputs of a
      * given derivation.
      */
-    boost::concurrent_flat_map<Hash, std::map<std::string, ref<UnkeyedRealisation>>> buildTrace;
+    boost::concurrent_flat_map<Hash, std::map<std::string, UnkeyedRealisation>> buildTrace;
 
     DummyStore(ref<const Config> config)
         : Store{*config}