webpack build slow

[davidlee0604]

when i build vue file use webpack --env.file=example.vue in windows, the build progress is very slow,block, command return message:
[4] ./node_modules/vue-style-loader!./node_modules/css-loader!./node_modules/vue-loader/lib/style-compiler?{"optionsId":"0","vue":true,"id":"data-v-3835be54","scoped":true,"sourceMap":false}!./node_modules/less-loader/dist/cjs.js!./node_mod
ules/vue-loader/lib/selector.js?type=styles&index=0!./src/example.vue 1.7 KiB {0} [built]
[] 85ms -> [] 711ms -> factory:383ms building:7ms = 1186ms

then, halt. i must ctrl+c to terminal the build command.