What does the warning «Use properties from the build variant packages» mean?

Question

What does this warning mean?

It is appeared in version 1.0.0-beta-3595 for all usages of kotlin android extensions in my code.

Answer 1

I think they did this to support multiple build variants. For example when you have a flavour proversion and you want to use a layout from that flavour you have to use

import kotlinx.android.synthetic.proversion.activity_main.*

For the main build variant you have to use

import kotlinx.android.synthetic.main.activity_main.*

Answer 2

Not strictly the answer to the question 'why did they do that', but that's how to eliminate warning. Change

import kotlinx.android.synthetic.activity_main.*

to

import kotlinx.android.synthetic.main.activity_main.*

implying that you already bumped version in build.gradle and updated IDEA (or AS) kotlin plugins.