We were building our own python-click package because we needed features/bug fixes available as of version 7.0.0, but the most recent version available from Debian was in the 6.x range.
"Click" is needed for building/testing and installing sonic-utilities. Now that we are building sonic-utilities as a wheel, with Click specified as a dependency in the setup.py file, setuptools will install a more recent version of Click in the sonic-slave-buster container when building the package, and pip will install a more recent version of Click in the host OS of SONiC when installing the sonic-utilities package. Also, we don't need to worry about installing the Python 2 or 3 version of the package, as the proper one will be installed as necessary.
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