build not exist while building a python package.

I'm following the documentation to build a python package. Here are the detailed steps.

(1)write a makesqr.m following the documentation

(2)use the libraryCompiler lauch the Library Compiler

(3)rename the library name to MagicSquarePkg

(4)In the Samples section, select Create New Sample

(5)Choose runtime downloaded from web

(6)Package

Here is the MagicSquarePkg file folder

As I steps into for_testing folder to run setup.py by

python setup.py install

There comes the error

running install
running build
running build_py
creating build
creating build/lib
creating build/lib/MagicSquarePkg
copying MagicSquarePkg/__init__.py -> build/lib/MagicSquarePkg
copying MagicSquarePkg/MagicSquarePkg.ctf -> build/lib/MagicSquarePkg
running install_lib
running install_egg_info
Removing /Users/shuhaojie/Library/Python/2.7/lib/python/site-packages/matlabruntimeforpython-R2019a-py2.7.egg-info
Writing /Users/shuhaojie/Library/Python/2.7/lib/python/site-packages/matlabruntimeforpython-R2019a-py2.7.egg-info
removing 'build/lib' (and everything under it)
'build/bdist.macosx-10.15-x86_64' does not exist -- can't clean it
'build/scripts-2.7' does not exist -- can't clean it
removing 'build'

My python2 version is Python 2.7.16.