Bench update issue - failing at Installing yarn

Hi,

Am getting this error while running bench update. Not sure what is causing this issue.

Sorry, user frappe is not allowed to execute ‘/usr/bin/npm install -g yarn’ as root on ip-172-31-17-136.us-west-2.compute.internal.
Traceback (most recent call last):
File “/usr/local/bin/bench”, line 11, in
load_entry_point(‘bench’, ‘console_scripts’, ‘bench’)()
File “/home/frappe/.bench/bench/cli.py”, line 40, in cli
bench_command()
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 722, in call
return self.main(*args, **kwargs)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 697, in main
rv = self.invoke(ctx)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 1066, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 895, in invoke
return ctx.invoke(self.callback, **ctx.params)
File “/usr/local/lib/python2.7/dist-packages/click/core.py”, line 535, in invoke
return callback(*args, **kwargs)
File “/home/frappe/.bench/bench/commands/update.py”, line 30, in update
patches.run(bench_path=‘.’)
File “/home/frappe/.bench/bench/patches/init.py”, line 21, in run
result = execute(bench_path)
File “/home/frappe/.bench/bench/patches/v4/install_yarn.py”, line 4, in execute
subprocess.check_output([‘sudo’, ‘npm’, ‘install’, ‘-g’, ‘yarn’])
File “/usr/lib/python2.7/subprocess.py”, line 574, in check_output
raise CalledProcessError(retcode, cmd, output=output)
subprocess.CalledProcessError: Command ‘[‘sudo’, ‘npm’, ‘install’, ‘-g’, ‘yarn’]’ returned non-zero exit status 1

I referred this site, Installation | Yarn, and ran these following commands:

curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
echo “deb https://dl.yarnpkg.com/debian/ stable main” | sudo tee /etc/apt/sources.list.d/yarn.list
sudo apt-get update && sudo apt-get install yarn

But, am still facing update issues. Can anyone please help?

Thanks
Uma