From 9eecee3d4e28634ef11d0044bb2e84bd8b13f2c7 Mon Sep 17 00:00:00 2001
From: Bernardo Meurer Costa <beme@anthropic.com>
Date: Wed, 1 Oct 2025 21:20:33 +0000
Subject: [PATCH] fix(libstore/build/derivation-goal): don't assert on
 partially valid outputs

Fixes: #14130
---
 src/libstore/build/derivation-goal.cc | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc
index 4beced6d8..717d6890a 100644
--- a/src/libstore/build/derivation-goal.cc
+++ b/src/libstore/build/derivation-goal.cc
@@ -278,7 +278,23 @@ Goal::Co DerivationGoal::haveDerivation(bool storeDerivation)
                 }
             }
 
-            assert(success.builtOutputs.count(wantedOutput) > 0);
+            /* If the wanted output is not in builtOutputs (e.g., because it
+               was already valid and therefore not re-registered), we need to
+               add it ourselves to ensure we return the correct information. */
+            if (success.builtOutputs.count(wantedOutput) == 0) {
+                debug(
+                    "BUG! wanted output '%s' not in builtOutputs, working around by adding it manually", wantedOutput);
+                success.builtOutputs = {{
+                    wantedOutput,
+                    {
+                        assertPathValidity(),
+                        {
+                            .drvHash = outputHash,
+                            .outputName = wantedOutput,
+                        },
+                    },
+                }};
+            }
         }
     }