EvalCache: Ignore SQLite errors

Fixes #3794.

src/libexpr/eval-cache.cc

@@ -19,6 +19,8 @@ create table if not exists Attributes (
 
 struct AttrDb
 {
+    std::atomic_bool failed{false};
+
     struct State
     {
         SQLite db;
@@ -64,6 +66,7 @@ struct AttrDb
     {
         try {
             auto state(_state->lock());
+            if (!failed)
                 state->txn->commit();
             state->txn.reset();
         } catch (...) {
@@ -71,9 +74,24 @@ struct AttrDb
         }
     }
 
+    template<typename F>
+    AttrId doSQLite(F && fun)
+    {
+        if (failed) return 0;
+        try {
+            return fun();
+        } catch (SQLiteError &) {
+            ignoreException();
+            failed = true;
+            return 0;
+        }
+    }
+
     AttrId setAttrs(
         AttrKey key,
         const std::vector<Symbol> & attrs)
+    {
+        return doSQLite([&]()
         {
             auto state(_state->lock());
 
@@ -94,12 +112,15 @@ struct AttrDb
                     (0, false).exec();
 
             return rowId;
+        });
     }
 
     AttrId setString(
         AttrKey key,
         std::string_view s,
         const char * * context = nullptr)
+    {
+        return doSQLite([&]()
         {
             auto state(_state->lock());
 
@@ -124,11 +145,14 @@ struct AttrDb
             }
 
             return state->db.getLastInsertedRowId();
+        });
     }
 
     AttrId setBool(
         AttrKey key,
         bool b)
+    {
+        return doSQLite([&]()
         {
             auto state(_state->lock());
 
@@ -139,9 +163,12 @@ struct AttrDb
                 (b ? 1 : 0).exec();
 
             return state->db.getLastInsertedRowId();
+        });
     }
 
     AttrId setPlaceholder(AttrKey key)
+    {
+        return doSQLite([&]()
         {
             auto state(_state->lock());
 
@@ -152,9 +179,12 @@ struct AttrDb
                 (0, false).exec();
 
             return state->db.getLastInsertedRowId();
+        });
     }
 
     AttrId setMissing(AttrKey key)
+    {
+        return doSQLite([&]()
         {
             auto state(_state->lock());
 
@@ -165,9 +195,12 @@ struct AttrDb
                 (0, false).exec();
 
             return state->db.getLastInsertedRowId();
+        });
     }
 
     AttrId setMisc(AttrKey key)
+    {
+        return doSQLite([&]()
         {
             auto state(_state->lock());
 
@@ -178,9 +211,12 @@ struct AttrDb
                 (0, false).exec();
 
             return state->db.getLastInsertedRowId();
+        });
     }
 
     AttrId setFailed(AttrKey key)
+    {
+        return doSQLite([&]()
         {
             auto state(_state->lock());
 
@@ -191,6 +227,7 @@ struct AttrDb
                 (0, false).exec();
 
             return state->db.getLastInsertedRowId();
+        });
     }
 
     std::optional<std::pair<AttrId, AttrValue>> getAttr(
@@ -237,12 +274,22 @@ struct AttrDb
     }
 };
 
+static std::shared_ptr<AttrDb> makeAttrDb(const Hash & fingerprint)
+{
+    try {
+        return std::make_shared<AttrDb>(fingerprint);
+    } catch (SQLiteError &) {
+        ignoreException();
+        return nullptr;
+    }
+}
+
 EvalCache::EvalCache(
     bool useCache,
     const Hash & fingerprint,
     EvalState & state,
     RootLoader rootLoader)
-    : db(useCache ? std::make_shared<AttrDb>(fingerprint) : nullptr)
+    : db(useCache ? makeAttrDb(fingerprint) : nullptr)
     , state(state)
     , rootLoader(rootLoader)
 {

src/libexpr/flake/flake.cc

@@ -63,7 +63,6 @@ static std::tuple<fetchers::Tree, FlakeRef, FlakeRef> fetchOrSubstituteTree(
     debug("got tree '%s' from '%s'",
         state.store->printStorePath(tree.storePath), lockedRef);
 
-
     if (state.allowedPaths)
         state.allowedPaths->insert(tree.actualPath);