Get rid of most `.at` calls (#6393)

Use one of `get` or `getOr` instead which will either return a null-pointer (with a nicer error message) or a default value when the key is missing.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 5cc5c91cc..eba3b0fa5 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -718,7 +718,11 @@ void LocalStore::checkDerivationOutputs(const StorePath & drvPath, const Derivat
                     // somewhat expensive so we do lazily
                     hashesModulo = hashDerivationModulo(*this, drv, true);
                 }
-                StorePath recomputed = makeOutputPath(i.first, hashesModulo->hashes.at(i.first), drvName);
+                auto currentOutputHash = get(hashesModulo->hashes, i.first);
+                if (!currentOutputHash)
+                    throw Error("derivation '%s' has unexpected output '%s' (local-store / hashesModulo) named '%s'",
+                        printStorePath(drvPath), printStorePath(doia.path), i.first);
+                StorePath recomputed = makeOutputPath(i.first, *currentOutputHash, drvName);
                 if (doia.path != recomputed)
                     throw Error("derivation '%s' has incorrect output '%s', should be '%s'",
                         printStorePath(drvPath), printStorePath(doia.path), printStorePath(recomputed));