[yocto] Raspberry Pi 3 build issue

[alexis.lothore at gmail.com]

Hello, 
I am currently encountering an issue with meta-raspberry and more 
specifically Raspberry Pi 3 build. Since I was not sure the problem was 
not my fault, I cloned a fresh copy of poky and meta-raspberrypi (both 
checked out on morty, and meta dependencies on morty too), but the problem 
is still appearing, trying to build the image rpi-hwup-image with BDISTRO 
poky for MACHINE 
raspberrypi3 :

➜ build git:(morty) bitbake rpi-hwup-image
Loading cache: 100% 
|#########################################################################################################################################################################################################| 
Time: 0:00:00
Loaded 2 entries from dependency cache.
WARNING: 
/home/alexis/Projets/poky/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.9.bb: 
Exception during build_dependencies for PKG_kernel-image | ETA: --:--:--
WARNING: 
/home/alexis/Projets/poky/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.9.bb: 
Error during finalise of 
/home/alexis/Projets/poky/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.9.bb
WARNING: 
/home/alexis/Projets/poky/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.4.bb: 
Exception during build_dependencies for PKG_kernel-image
WARNING: 
/home/alexis/Projets/poky/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.4.bb: 
Error during finalise of 
/home/alexis/Projets/poky/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.4.bb
ERROR: ExpansionError during parsing 
/home/alexis/Projets/poky/meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.9.bb
Traceback (most recent call last):
bb.data_smart.ExpansionError: Failure expanding variable PKG_kernel-image, 
expression was 
kernel-image-${@legitimize_package_name('${@get_kernelversion_headers('/home/alexis/Projets/poky/build/tmp/work/raspberrypi3-poky-linux-gnueabi/linux-raspberrypi/1_4.9.21+git${SRCPV}-r0/linux-raspberrypi3-standard-build')}')} 
which triggered exception SyntaxError: invalid syntax (PKG_kernel-image, 
line 1)
Summary: There were 4 WARNING messages shown.
Summary: There was 1 ERROR message shown, returning a non-zero exit code.

I am executing the build on an x86 machine with Debian 8.

Unfortunately, since the problem seems to appear right at parsing, I 
cannot get the exact variable expansion with bitbake -e. Apparently my 
Yocto setup does not encounter the issue if I try the build for another 
RPI target, like raspberrypi0. Any advice on how to troubleshoot this 
issue ?