This issue happens on production of one user that enabled Sentry:

![Screenshot_20210303_002028](https://user-images.githubusercontent.com/18581488/109716945-7f9a1200-7bb6-11eb-8cf4-1080ad535d18.png)

Build id: 49938CCB63EE2A4E16CF0528307EE15F08469219.
column_type = makeNullable(column_type);
            }
            column_names_and_types.emplace_back(col_decl.name, column_type);
        }
        else
        {
            
            column_names_and_types.emplace_back(col_decl.name, std::make_shared<DataTypeUInt8>());
        }
        
        if (col_decl.default_expression)
        {
            /** For columns with explicitly-specified type create two expressions:
              * 1. default_expression aliased as column name with _tmp suffix
              * 2. conversion of expression (1) to explicitly-specified type alias as column name
              */
            if (col_decl.type)
            {
                const auto & final_column_name = col_decl.name;
                const auto tmp_column_name = final_column_name + "_tmp_alter" + toString(randomSeed());
                const auto * data_type_ptr = column_names_and_types.back().type.get();
                default_expr_list->children.emplace_back(
                    setAlias(addTypeConversionToAST(std::make_shared<ASTIdentifier>(tmp_column_name), data_type_ptr->getName()),
                        final_column_name));
                default_expr_list->children.emplace_back(
                    setAlias(
                        col_decl.default_expression->clone(),
                        tmp_column_name));
            }
            else