From e764ed31f61308690a9a8a5dc6f20e570b7de262 Mon Sep 17 00:00:00 2001
From: Lexi Mattick <lexi.mattick@neuralink.com>
Date: Fri, 12 Jul 2024 09:45:35 -0700
Subject: [PATCH] Eval cache: fix cache regressions

- Fix eval cache not being persisted in `nix develop` (since #10570)
- Don't attempt to commit cache transaction if there is no active transaction, which will spew errors in edge cases
- Drive-by: trivial typo fix
---
 src/libcmd/installable-value.hh | 2 +-
 src/libexpr/eval-cache.cc       | 2 +-
 src/nix/develop.cc              | 4 ++++
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/libcmd/installable-value.hh b/src/libcmd/installable-value.hh
index f300d392b..798cb5e1a 100644
--- a/src/libcmd/installable-value.hh
+++ b/src/libcmd/installable-value.hh
@@ -66,7 +66,7 @@ struct ExtraPathInfoValue : ExtraPathInfo
 };
 
 /**
- * An Installable which corresponds a Nix langauge value, in addition to
+ * An Installable which corresponds a Nix language value, in addition to
  * a collection of \ref DerivedPath "derived paths".
  */
 struct InstallableValue : Installable
diff --git a/src/libexpr/eval-cache.cc b/src/libexpr/eval-cache.cc
index 2630c34d5..5085fedc2 100644
--- a/src/libexpr/eval-cache.cc
+++ b/src/libexpr/eval-cache.cc
@@ -95,7 +95,7 @@ struct AttrDb
     {
         try {
             auto state(_state->lock());
-            if (!failed)
+            if (!failed && state->txn->active)
                 state->txn->commit();
             state->txn.reset();
         } catch (...) {
diff --git a/src/nix/develop.cc b/src/nix/develop.cc
index 6bd3dc9ef..b89de5d5c 100644
--- a/src/nix/develop.cc
+++ b/src/nix/develop.cc
@@ -697,6 +697,10 @@ struct CmdDevelop : Common, MixEnvironment
             }
         }
 
+        // Release our references to eval caches to ensure they are persisted to disk, because
+        // we are about to exec out of this process without running C++ destructors.
+        getEvalState()->evalCaches.clear();
+
         runProgramInStore(store, UseLookupPath::Use, shell, args, buildEnvironment.getSystem());
 #endif
     }