I am trying to install micropython-umqtt.robust on my Wemos D1 mini.
The way i tried this is as follow.
I use the Thonny editor

I have connected the wemos to the internet.
in wrepl type:
import upip
upip.install('micropython-umqtt.simple')
I get the folowing error: Installing to: /lib/
Error installing 'micropython-umqtt.simple': Package not found, packages may be partially        installed
upip.install('micropython-umqtt.robust')
I get the folowing error: Error installing 'micropython-umqtt.robust': Package not found,   packages may be partially installed

Can umqtt be installed on Wemos D1 mini ? if yes how do I do this ?
I think the MicroPython build available from micropython.org already bundles MQTT so no need to install it with upip. Try this directly from the REPL:
from umqtt.robust import MQTTClient
or
from umqtt.simple import MQTTClient
and start using it from there
mqtt = MQTTClient(id, server, user, password)
umqtt.robust on Wemos