error page show twice

[Topthinking]

production next build && next start

I will show the error page, so I write wrong code to show the error page and to run 'shell' . server render error and this error do not mount error component

server/render.js fn: doRender

try {
      html = render(app)
      console.log('',html)
    } finally {
      console.log('render error')
      head = Head.rewind() || defaultHead()
    }    

_error.js

import React from 'react'

class ErrorPage extends React.Component {
  static getInitialProps ({ res, jsonPageRes,err }) {
    const status = res ? res.statusCode : (jsonPageRes ? jsonPageRes.status : null)
    return { status ,err}
  }

  render() {
    console.log("catch error \r\n", this.props.err)
    return <h1>error page</h1>
  }
}

export default ErrorPage

index.js

import React from 'react'

const data = [{
  name: 'top'
}, {
  name: 'syj'
}]

const datas = data[0]

export default class Index extends React.Component {

  render() {
    return (
      <div>
        {
          datas.map(item => {
            return <span key={item.name}>{item.name}</span>
          })
        }
      </div>
    )
  }
}

 "next_run":"NODE_ENV=production next build && next start"

page show this

<div><div id="__next">
<div data-reactroot="" data-reactid="1" data-react-checksum="2060458764">
<h1 data-reactid="2">error page</h1>
</div>
</div>
<div id="__next-error">
<h1 data-reactroot="">error page</h1>
</div>
</div>

show twice

What am I supposed to do

[oliviertassinari]

@timneutkens Thanks for taking care of this ❤️ . I can remove my hack:

-  // Only render the error message on the server.
-  // Next.js append the server side and client side version.
-  // We don't want to display both.
-  if (statusCode !== 404 && process.browser) {
-    return null
-  }

[timneutkens]

@oliviertassinari 👌 🙌