No pyproject.toml, nothing installed: freeze_output: | # empty expected: | python3dist(setuptools) >= 40.8 python3dist(wheel) result: 0 Nothing installed yet: freeze_output: | # empty pyproject.toml: | # empty expected: | python3dist(setuptools) >= 40.8 python3dist(wheel) result: 0 Insufficient version of setuptools: freeze_output: | setuptools==5 wheel==1 pyproject.toml: | # empty expected: | python3dist(setuptools) >= 40.8 python3dist(wheel) result: 0 Empty pyproject.toml, empty setup.py: freeze_output: | setuptools==50 wheel==1 setup.py: | expected: | python3dist(setuptools) >= 40.8 python3dist(wheel) python3dist(wheel) result: 0 Default build system, empty setup.py: freeze_output: | setuptools==50 wheel==1 pyproject.toml: | # empty setup.py: | expected: | python3dist(setuptools) >= 40.8 python3dist(wheel) python3dist(wheel) result: 0 Erroring setup.py: freeze_output: | setuptools==50 wheel==1 setup.py: | exit(77) result: 77 Bad character in version: freeze_output: | pyproject.toml: | [build-system] requires = ["pkg == 0.$.^.*"] except: ValueError Build system dependencies in pyproject.toml: freeze_output: | setuptools==50 wheel==1 pyproject.toml: | [build-system] requires = [ "foo", "ne!=1", "ge>=1.2", "le <= 1.2.3", "lt < 1.2.3.4 ", " gt > 1.2.3.4.5", "combo >2, <5, != 3.0.0", "invalid!!ignored", "py2 ; python_version < '2.7'", "py3 ; python_version > '3.0'", "pkg [extra-currently-ignored]", ] expected: | python3dist(foo) (python3dist(ne) < 1 or python3dist(ne) > 1.0) python3dist(ge) >= 1.2 python3dist(le) <= 1.2.3 python3dist(lt) < 1.2.3.4 python3dist(gt) > 1.2.3.4.5 ((python3dist(combo) < 3 or python3dist(combo) > 3.0) and python3dist(combo) < 5 and python3dist(combo) > 2) python3dist(py3) python3dist(pkg) python3dist(setuptools) >= 40.8 python3dist(wheel) result: 0 Default build system, dependencies in setup.py: freeze_output: | setuptools==50 wheel==1 setup.py: | from setuptools import setup setup( name='test', version='0.1', setup_requires=['foo', 'bar!=2'], ) expected: | python3dist(setuptools) >= 40.8 python3dist(wheel) python3dist(wheel) python3dist(foo) (python3dist(bar) < 2 or python3dist(bar) > 2.0) result: 0