https://github.com/python/typeshed/blob/cb27610970eb6ed146731a42a581961bb702adc2/stubs/setuptools/setuptools/_distutils/ccompiler.pyi#L19 Should be `obj_extension` (no `s`), see https://github.com/pypa/setuptools/blob/e4cca0e16d4080289bff6719e5e8ffc82164148a/setuptools/_distutils/ccompiler.py#L74
typeshed/stubs/setuptools/setuptools/_distutils/ccompiler.pyi
Line 19 in cb27610
Should be
obj_extension(nos), see https://github.com/pypa/setuptools/blob/e4cca0e16d4080289bff6719e5e8ffc82164148a/setuptools/_distutils/ccompiler.py#L74