blinky app won't build unless upgrading to newer arm-toolchain

[manish-sudo]

Following instructions here if I install the 4.9 arm toolchain, and build the app, I get following error message:

$ newt create-image nrf52_blinky 1.0.0
Compiling repos/apache-mynewt-core/hw/drivers/uart/src/uart.c
Assembling repos/apache-mynewt-core/hw/bsp/nordic_pca10040/src/arch/cortex_m4/gcc_startup_nrf52.s
Assembling repos/apache-mynewt-core/hw/bsp/nordic_pca10040/src/arch/cortex_m4/gcc_startup_nrf52_split.s
Compiling repos/apache-mynewt-core/hw/bsp/nordic_pca10040/src/sbrk.c
Compiling repos/apache-mynewt-core/hw/hal/src/hal_common.c
. . .
. . .
Compiling repos/apache-mynewt-core/libc/baselibc/src/memfile.c
Compiling repos/apache-mynewt-core/libc/baselibc/src/memmem.c
Error: repos/apache-mynewt-core/kernel/os/src/os_mempool.c: In function 'os_memblock_from':
repos/apache-mynewt-core/kernel/os/src/os_mempool.c:308:5: error: implicit declaration of function 'static_assert' [-Werror=implicit-function-declaration]
static_assert(sizeof block_addr == sizeof baddr32,
^
cc1: all warnings being treated as errors

After advancing the toolchain to "version 8.2.1 20181213", the above mentioned problem was resolved. So, I think the document should be updated to avoid this issue.

[utzig]

I would suggest updating the docs to install whatever is latest: brew install gcc-arm-none-eabi (with no version given). It's very unlikely that a newer version of gcc will be breaking our builds, and if it does there's way more chance that we fix the broken build before we fix docs.

[manish-sudo]

Makes sense!