Cause

cause.go

package main

import (
	"context"
	"errors"
	"log"
)


func main() {
	ctx, cancelWithCause := context.WithCancelCause(context.Background())
	cancelWithCause(errors.New("error: cancellation cause"))

	<-ctx.Done()
	log.Println(ctx.Err())
	log.Println(context.Cause(ctx))
}