Project properties undefined inside Group

We are using unstable qbs from master for daily builds, and suddenly everything fell apart.

After a bit of investigation I figured that project properties no longer work inside Group {} item.

Small example:
http://paste.ubuntu.com/23573357/

This is output from 1.7 (beginning of november build):

src/bin/bin.qbs, destinationDirectory
qutim_bin_path = bin
project.qutim_bin_path = bin

src/bin/bin.qbs, destinationDirectory
qutim_bin_path = bin
project.qutim_bin_path = bin

src/bin/bin.qbs, Group -> qbs.installDir
!typeof qutim_bin_path = string
!qutim_bin_path = bin
!project.qutim_bin_path = bin
!typeof parent = undefined

Setting up build graph for configuration default
Building for configuration default
compiling main.cpp
linking qutim
Build done for configuration default.

This is output from 1.8:

src/bin/bin.qbs, destinationDirectory
qutim_bin_path = bin
project.qutim_bin_path = bin

src/bin/bin.qbs, destinationDirectory
qutim_bin_path = bin
project.qutim_bin_path = bin

src/bin/bin.qbs, Group -> qbs.installDir
!typeof qutim_bin_path = undefined
!project.qutim_bin_path = bin
!typeof parent = undefined
ERROR: /home/nico-izo/qbspackage/qbs-qutim-scope/src/bin/bin.qbs:22:25 ReferenceError: Can't find variable: qutim_bin_path

So, my suggestions are:
1.) This is a bug
2.) Something changed and it's not a bug, so I should never use project properties without explicit "project."

P.S. Apparently this is also the case in latest build of 1.7.0 from QtCreator 4.2 RC. Sorry for the confusion, I have too old 1.7.0 build.