TypeError: /home/parse/Taotie/views/front/layouts/_header.pug:43
   41|                         .sub-nav-list
   42|                             ul.lv1-list
 > 43|                                 each category in categories
   44|                                     li.lv1-item
   45|                                         a(href='/category/'+category.main.id) #{category.main.name}
   46|                                         .collapse-button

Cannot read property 'length' of undefined
   at eval (eval at wrap (/home/parse/Taotie/node_modules/pug-runtime/wrap.js:9:4), <anonymous>:214:31)
   at eval (eval at wrap (/home/parse/Taotie/node_modules/pug-runtime/wrap.js:9:4), <anonymous>:321:4)
   at template (eval at wrap (/home/parse/Taotie/node_modules/pug-runtime/wrap.js:9:4), <anonymous>:461:72)
   at Object.exports.renderFile (/home/parse/Taotie/node_modules/pug/lib/index.js:428:38)
   at Object.exports.renderFile (/home/parse/Taotie/node_modules/pug/lib/index.js:418:21)
   at View.exports.__express [as engine] (/home/parse/Taotie/node_modules/pug/lib/index.js:465:11)
   at View.render (/home/parse/Taotie/node_modules/express/lib/view.js:126:8)
   at tryRender (/home/parse/Taotie/node_modules/express/lib/application.js:639:10)
   at EventEmitter.render (/home/parse/Taotie/node_modules/express/lib/application.js:591:3)
   at ServerResponse.render (/home/parse/Taotie/node_modules/express/lib/response.js:961:7)