[3.11] gh-95913: Consolidate build requirements changes in 3.11 WhatsNew (GH-98781) by miss-islington · Pull Request #102497 · python/cpython
* Building Python now requires: * Building CPython now requires:
* A `C11 <https://en.cppreference.com/w/c/11>`_ compiler. * A `C11 <https://en.cppreference.com/w/c/11>`_ compiler and standard library. `Optional C11 features <https://en.wikipedia.org/wiki/C11_(C_standard_revision)#Optional_features>`_ are not required. (Contributed by Victor Stinner in :issue:`46656`.) (Contributed by Victor Stinner in :issue:`46656`, :issue:`45440` and :issue:`46640`.)
* Support for `IEEE 754 <https://en.wikipedia.org/wiki/IEEE_754>`_ floating point numbers. (Contributed by Victor Stinner in :issue:`46917`.)
* Support for `floating point Not-a-Number (NaN) <https://en.wikipedia.org/wiki/NaN#Floating_point>`_, as the :c:macro:`!Py_NO_NAN` macro has been removed. (Contributed by Victor Stinner in :issue:`46656`.)
* A `C99 <https://en.cppreference.com/w/c/99>`_ ``<math.h>`` header file providing the :c:func:`!copysign`, :c:func:`!hypot`, :c:func:`!isfinite`, :c:func:`!isinf`, :c:func:`!isnan`, and :c:func:`!round` functions (contributed by Victor Stinner in :issue:`45440`); and a :c:data:`!NAN` constant or the :c:func:`!__builtin_nan` function (Contributed by Victor Stinner in :issue:`46640`). * The :c:macro:`!Py_NO_NAN` macro has been removed. Since CPython now requires IEEE 754 floats, NaN values are always available. (Contributed by Victor Stinner in :issue:`46656`.)
* The :mod:`tkinter` package now requires `Tcl/Tk <https://www.tcl.tk>`_ version 8.5.12 or newer.