fix: Copy directory (ava-labs/coreth#1376) (#1846)

Author: alarso16

core/blockchain_ext_test.go

@@ -2076,10 +2076,9 @@ func ReexecCorruptedStateTest(t *testing.T, create ReexecTestFunc) {
 	blockchain.Stop()
 
 	// Restart blockchain with existing state
-	restartedBlockchain, err := create(chainDB, gspec, chain[1].Hash(), tempDir, 4096)
-	if err != nil {
-		t.Fatalf("failed to restart blockchain: %v", err)
-	}
+	newDir := copyFlatDir(t, tempDir) // avoid file lock
+	restartedBlockchain, err := create(chainDB, gspec, chain[1].Hash(), newDir, 4096)
+	require.NoError(t, err)
 	defer restartedBlockchain.Stop()
 
 	// We should be able to accept the remaining blocks