Getting error on discord bot discord.py for typing in role

I get this error on my bot when mentioning a role,here is the error,

raise CommandInvokeError(exc) from exc discord.ext.commands.errors.CommandInvokeError: Command raised an exception: TypeError: unhashable type: ‘set’

my code:

import os
import discord
from discord.ext import commands
from discord import Intents
from apikeys import *
intents = Intents.all()
client = commands.Bot(intents = intents, command_prefix="-", case_insensitive=True)
 

 
@client.event
async def on_ready():
    for emoji in client.emojis:
        print("Name:", emoji.name + ",", "ID:", emoji.id)
    print('Bot is Online {0.user}'.format(client))
    print("--------------------------------------------------------------------------------------------------------------------------------------------------------")
client.remove_command('help')
 
 
emojigood = 'N{THUMBS UP SIGN}'
emojibad="N{THUMBS DOWN SIGN}"
 
@client.command()
async def war(ctx):
  await client.wait_until_ready()
  embed = discord.Embed(title='War', description='You are starting a war, do you want to continue?', color=0x00000)
  msg = await ctx.send(embed=embed)
  await msg.add_reaction(emojigood)
  await msg.add_reaction(emojibad)
  def check(r, user):
    return (r.emoji == emojigood or r.emoji == emojibad) and r.message == msg and user != client.user
  r, user = await client.wait_for('reaction_add',check=check)
  if r.emoji == emojigood:
    embed = discord.Embed(title='War', description='Please now choose a country', color=0x00000)
    await ctx.send(embed=embed)
    def check(msg):
      return msg.author == ctx.author and msg.channel == ctx.channel
    msg = await client.wait_for('message', check=check)
    if len(msg.role_mentions) > 0:
      role = msg.role_mentions[0]
      channel = client.get_channel({849549009038344262})
      await channel.send(f"{role.mention} {ctx.author} has declared war on you.")
    else:
      await ctx.send("Invalid role mentioned")
  else:
    await ctx.send("Cancelled")
 
 
client.run(token)

What’s meant to happen: Me:-war Bot:Are you sure Me:reacts Bot:Type in role Me:(role name) Bot:….

Answer

{849549009038344262}

is a set literal for a set containing a number. discord.py is using hashing under the hood to look up channels, which is failing because it is not possible to hash sets. You should be passing a regular int instead of a set:

channel = client.get_channel(849549009038344262)