How to make apq8084

1.first of all, you'll meet many problem no excute permisson,pls do:
Chmod-r +x apq8084/

2. BUILD/CORE/BASE_RULES.MK:130: * * * external/webrtc/src/system_wrappers/source:module. TARGET. Static_libraries.libwebrtc_system_wrappers already defined by External/webrtc/src/system_wrappers/source. Stop.

pls do:
"Unset ndk_root"
As apparently there is a bug in the WEBRTC makefiles that causes it to ignore including STL if the Ndk_root environmental variable is previously defined (by ~/.BASHRC, in my case). So just make sure ndk_root are not defined on all when building

3. Don't use the shell named build.sh in APQ8084 root directory
Improve compile speed by below operation:
A. Modify ~/.BASHRC, add "export Use_ccache = 1"
B. Prebuilts/misc/linux-x86/ccache/ccache-m 50G

Then compile:
SOURCE build/envsetup.sh;
Lunch Pls choose apq8084
Make-j8

How to make apq8084