TDA4VMXEVM: Building filesystem via yocto failed: Failed to obtain external ARM toolchain version

Part Number: TDA4VMXEVM

Hello,

I've worked recently a lot with yocto/arago for AM65* Sitara plattform. Now I try to move to Jactino 7 plattform. I have a TDA4VMXEVM and had some problems to configure arago in the correct way:

I've followed the steps described in PSDKLA version 06_01_01_02 :

http://software-dl.ti.com/jacinto7/esd/processor-sdk-linux-jacinto7/latest/exports/docs/linux/Overview_Building_the_SDK.html#build-steps

I downloaded and extracted the ARMv7 and ARMv8 toolchain to ~/oe/crosstoolchain.

However, the final command to build the image

TOOLCHAIN_BASE=/home/ewdt/oe/crosstoolchain MACHINE=j7-evm bitbake -k tisdk-rootfs-image

resulted in this error of bitbake:

ERROR: Failed to obtain external Arm toolchain version: Execution of '/opt/gcc-arm-8.3-2019.03-x86_64-aarch64-linux-gnu/bin/aarch64-linux-gnu-gcc -v' failed: command not found

After a bit of research, I found that TOOLCHAIN_BASE was not set by me, although I've executed the command above.

sources/meta-arago/meta-arago-distro/conf/distro/include/toolchain-linaro.inc:TOOLCHAIN_BASE ?= "/opt"
This include file sets it to "/opt" if it was not set previous.

I fixed the issue finally with adding "TOOLCHAIN_BASE = "/home/ewdt/oe/crosscompiletoolchain" to my build/conf/local.conf but I wonder why it does not work as described in PSDKLA?
Maybe this will help others facing the same problem.