Linux Boot2Qt_Jethro build failed

This is the Qt Open Source Edition.

You have already accepted the terms of the Open Source license.
Command line: 

Running configuration tests...
Checking for gold linker... 
+ cd /home/qt/work/qt/qt5/qtbase/config.tests && g++ -fuse-ld=gold -o conftest-out conftest.cpp
test config.qtbase.tests.use_gold_linker succeeded
Checking for machine tuple... 
+ g++ -dumpmachine
> x86_64-linux-gnu
test config.qtbase.tests.machineTuple succeeded
Checking for valid makespec... 
+ cd /home/qt/work/qt/qt5/qtbase/config.tests/common/verifyspec && /home/qt/work/qt/qt5/qtbase/bin/qmake "CONFIG -= qt debug_and_release app_bundle lib_bundle" "CONFIG += shared use_gold_linker console single_arch" /home/qt/work/qt/qt5/qtbase/config.tests/common/verifyspec
> Project ERROR: CROSS_COMPILE needs to be set via -device-option CROSS_COMPILE=<path>
Note: Also available for Linux: linux-clang linux-kcc linux-icc linux-cxx

ERROR: Cannot compile a minimal program. The toolchain or QMakeSpec is broken.

agent:2017/01/31 22:27:28 build.go:200: Process finished with error: exit status 3
agent:2017/01/31 22:27:28 agent.go:160: Build failed
agent:2017/01/31 22:27:28 agent.go:117: ERROR building: exit status 3
agent:2017/01/31 22:27:28 build.go:152: Error reading from stdout/err: exit status 3