# Buggy code
def _run_command(
    self,
    host,
    command,
    sudo=False,
    user=None,
    shell=None,
    use_pty=False,
    encoding="utf-8",
    timeout=None,
):
    """Make SSHClient if needed, run command on host"""
    try:
        self._make_ssh_client(host)
        return self.host_clients[host].run_command(
            command,
            sudo=sudo,
            user=user,
            shell=shell,
            use_pty=use_pty,
            encoding=encoding,
            timeout=timeout,
        )
    except Exception as ex:
        ex.host = host
        logger.error("Failed to run on host %s - %s", host, ex)
        raise ex


# Traceback (ValueError)
Traceback (most recent call last):
File "./aws-instances", line 172, in <module>
main()
File "./aws-instances", line 73, in main
facts = remote_facts(ips)
File "./aws-instances", line 146, in remote_facts
out_kern = client.run_command('uname -r')
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/native/parallel.py", line 223, in run_command
greenlet_timeout=greenlet_timeout)
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/base_pssh.py", line 96, in run_command
self.get_output(cmd, output, timeout=greenlet_timeout)
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/base_pssh.py", line 141, in get_output
(channel, host, stdout, stderr, stdin) = cmd.get(timeout=timeout)
File "src/gevent/greenlet.py", line 709, in gevent._greenlet.Greenlet.get
File "src/gevent/greenlet.py", line 317, in gevent._greenlet.Greenlet._raise_exception
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/gevent/_compat.py", line 47, in reraise
raise value.with_traceback(tb)
File "src/gevent/greenlet.py", line 766, in gevent._greenlet.Greenlet.run
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/native/parallel.py", line 237, in _run_command
raise ex
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/native/parallel.py", line 233, in _run_command
use_pty=use_pty, encoding=encoding, timeout=timeout)
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/native/single.py", line 442, in run_command
channel = self.execute(_command, use_pty=use_pty)
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/native/single.py", line 324, in execute
channel = self.open_session() if channel is None else channel
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/pssh/clients/native/single.py", line 297, in open_session
wait_select(self.session)
File "pssh/native/_ssh2.pyx", line 171, in pssh.native._ssh2.wait_select
File "/home/user/do-aws-ec2-facts/aws/lib64/python3.6/site-packages/gevent/select.py", line 145, in select
sel_results = _original_select(rlist, wlist, xlist, 0)
ValueError: filedescriptor out of range in select()

# Fixed code
def _run_command(
    self,
    host_i,
    host,
    command,
    sudo=False,
    user=None,
    shell=None,
    use_pty=False,
    encoding="utf-8",
    timeout=None,
):
    """Make SSHClient if needed, run command on host"""
    try:
        self._make_ssh_client(host_i, host)
        return self._host_clients[(host_i, host)].run_command(
            command,
            sudo=sudo,
            user=user,
            shell=shell,
            use_pty=use_pty,
            encoding=encoding,
            timeout=timeout,
        )
    except Exception as ex:
        ex.host = host
        logger.error("Failed to run on host %s - %s", host, ex)
        raise ex