Click 8.0.0 uses 'mkstemp()' instead of the deprecated & insecure 'mktemp()'.
https://github.com/pallets/click/issues/1752

Pyyaml version 5.4 includes a fix for CVE-2020-14343: A vulnerability was discovered in the PyYAML library in versions before 5.4, where it is susceptible to arbitrary code execution when it processes untrusted YAML files through the full_load method or with the FullLoader loader. Applications that use the library to process untrusted input may be vulnerable to this flaw. This flaw allows an attacker to execute arbitrary code on the system by abusing the python/object/new constructor. This flaw is due to an incomplete fix for CVE-2020-1747.
https://bugzilla.redhat.com/show_bug.cgi?id=1860466

Pytest-runner depends on deprecated features of setuptools and relies on features that break security mechanisms in pip. For example ‘setup_requires’ and ‘tests_require’ bypass pip --require-hashes. See also pypa/setuptools#1684.
It is recommended that you:
- Remove 'pytest-runner' from your setup_requires, preferably removing the setup_requires option.
- Remove 'pytest' and any other testing requirements from tests_require, preferably removing the tests_requires option.
- Select a tool to bootstrap and then run tests such as tox.
https://github.com/pytest-dev/pytest-runner/blob/289a77b179535d8137118e3b8591d9e727130d6d/README.rst