add `pylint` to catch unused args

Makefile

@@ -130,9 +130,11 @@ codespell:
 	codespell . --skip ./.git -I .codespell-whitelist
 
 # TODO: add future protocol upgrade patch packages to linting.
+# NOTE: we use `pylint` just for catching unused arguments in spec code
 lint: pyspec
 	. venv/bin/activate; cd $(PY_SPEC_DIR); \
 	flake8  --config $(LINTER_CONFIG_FILE) ./eth2spec \
+	&& pylint --disable=all --enable unused-argument ./eth2spec/phase0 ./eth2spec/altair ./eth2spec/bellatrix \
 	&& mypy --config-file $(LINTER_CONFIG_FILE) -p eth2spec.phase0 -p eth2spec.altair -p eth2spec.bellatrix
 
 lint_generators: pyspec

setup.py

@@ -1008,7 +1008,7 @@ setup(
     python_requires=">=3.8, <4",
     extras_require={
         "test": ["pytest>=4.4", "pytest-cov", "pytest-xdist"],
-        "lint": ["flake8==3.7.7", "mypy==0.812"],
+        "lint": ["flake8==3.7.7", "mypy==0.812", "pylint==2.12.2"],
         "generator": ["python-snappy==0.5.4"],
     },
     install_requires=[