kbuild overwrites $CC

[Martin Kaiser]

Dear all,

I'm trying to compile busysbox with a toolchain created from
yoctoproject. This toolchain comes with a setup script to set $CC and
cross-compiler related environment variables. If the toolchain is
installed to a non-standard path, $CC contains the --sysroot parameter,
e.g.

martin at vagrant-ubuntu-trusty-32:~/src/busybox$ echo $CC
arm-poky-linux-gnueabi-gcc -march=armv5te -marm -mthumb-interwork --sysroot=/opt/poky-1.7.3/sysroots/armv5te-poky-linux-gnueabi

Busybox' Makefile unconditionally overwrites CC with

CC              = $(CROSS_COMPILE)gcc

CROSS_COMPILE ist set up correctly in the environment, so I get the
right compiler but the --sysroot parameter is stripped. As the include
path depends on sysroot, the compiler doesn't find some include files
and busybox compilation fails.

Do you have an idea how this is supposed to work? Should I submit a
patch that replaces CC = ... with CC ?= ... ;-)

Thanks,
Martin