Vuepress: Invalid configuration Port parameter

[busyrat]

• [ ] I confirm that this is an issue rather than a question.

Bug report

Steps to reproduce

Upgrade to 1.0.3 Configuring port in config.js is invalid

What is expected?

What is actually happening?

Other relevant information

• Output of npx vuepress info in my VuePress project:

[kefranabg]

Hi @busyrat,

Could you translate your issue so more people can help you?

[busyrat]

@kefranabg
Sorry, I have changed
English is not good /(ㄒoㄒ)/~~

[OverTree]

@think2011
you should look at this
[email protected] returns random port

[fancyfx]

This is a problem with [email protected],I try re-install vuepress solved this problem。
Because portfinder v1.0.23 fixed this bug.
check your portfinder version:

yarn list portfinder 
or 
npm list | grep portfinder