Why is EPIPE Koa js thrown out when redirecting?

Question

Node.js

Good afternoon, you need to make a redirect for SSR to Koa.js.
Conditions for a redirect, if the user went to the main page from a qver, for example, site.ru/?test, then there will be a redirect to the main site.ru.
Everything works fine on the locale, but on the test it crashes with an error:

Component code:
https://pastebin.com/3SHxjWR2
The redirect is done from lines 29-32. I check if there is a queristring, if there is, then I redirect to the main one.

According to this log from the test, then it enters the condition (mk 2 log console)
Please tell me where to dig? I do not quite understand the essence of the epipe error

Answer 1

So, added return and everything worked on the test

console.log(ctx.request.query, ctx.request.querystring);
  if (ctx.request.querystring && ctx.request.querystring !== 'auth-need') {
    console.log(ctx.request.query, ctx.request.querystring);
    ctx.redirect('/');
     return;
  }

But can someone explain to me why it helped?
I myself don’t see it yet, but the code after the redirect must be excluded, it sent the headers and then you can’t send anything