Tool Suite Build Failed - machine 'arm64-apple' not recognized

[Jay Zhu]

Hi,
I am a student new to RTEMS and trying to get my first lines to run. When following the quick-start guide, I was stuck in Install Tool Suite procedure. Using this command:
../source-builder/sb-set-builder --prefix=$HOME/quick-start/rtems/6 6/rtems-sparc
The output was:

error: building expat-2.1.0-arm64-apple-darwin21.4.0-1
Build FAILED
  See error report: rsb-report-expat-2.1.0-arm64-apple-darwin21.4.0-1.txt

Then I lookup the log file, in which the errors are:

Invalid configuration `arm64-apple-darwin21.4.0': machine `arm64-apple' not recognized
configure: error: /bin/sh conftools/config.sub arm64-apple-darwin21.4.0 failed
checking build system type... 
checking build system type... 
shell cmd failed: /bin/sh -ex  /Users/Jay/quick-start/src/rsb/rtems/build/expat-2.1.0-arm64-apple-darwin21.4.0-1/do-build
error: building expat-2.1.0-arm64-apple-darwin21.4.0-1

Can you kindly tell me how can I fix this?

Sincere,
Jinghui