After clean installation of MacOS 10.14 Mojave and Sourcetree external diff isn't working.
After some investigation it isn't working because of security settings - for some reason Sourcetree isn't asking for additional permissions to control other apps. I've checked on old computer which was updated from previous versions of MacOS and I see that there is entry for Sourcetree in Settings > Security & Privacy > Automation. While on new installation of MacOS Mojave new record isn't adding.
New MacOS Mojave installation:

Old MacOS which was upgraded from previous versions:

And I don't see way on how to add Sourcetree there, it looks like Sourcetree should ask for this permission. Is there any solution for this?