Wind River Support Network

Description

Problem Description
======================
Build wrlinux platform projects with shared sstate caches, if there is no change in wrlinux layers, all packages can be built from sstate except linux-windriver.

Expected Behavior
======================
The kernel should be built from sstate if there is no change.

Observed Behavior
======================
linux-windriver is always built from source even nothing is changed.

[wr-taf@pek-lpgtest11 qemux86-64-prj02]$ find -L build -type f -name log.do_compile
build/linux-windriver/temp/log.do_compile

[wr-taf@pek-lpgtest11 qemux86-64-prj02]$ find -L build -type f -name log.do_populate_sysroot_setscene | wc -l
138

Misc
======================
The issue doesn't occur on standard kernel:
[wr-taf@pek-lpgtest11 qemux86-64-std-2]$ find -L build -type f -name log.do_compile | wc -l
0

Steps to Reproduce

step 1; mkdir SSTATE_SCP
step 2; mkdir prj01 && cd prj01
configure --enable-board=qemux86-64 --enable-kernel=secure --enable-rootfs=secure-core --with-sstate-dir=/path/to/SSTATE_SCP --enable-parallel-pkgbuilds=8 --enable-jobs=8
make fs

Don't make any change.

step 3; mkdir prj02 && cd prj02
Configure and build new project with same options of step 2.
configure --enable-board=qemux86-64 --enable-kernel=secure --enable-rootfs=secure-core --with-sstate-dir=/path/to/SSTATE_SCP --enable-parallel-pkgbuilds=8 --enable-jobs=8

step 4; check that all packages are built from sstate
find -L build -type f -name log.do_compile

No compile log should be found.