Improving `./configure --help` output

./configure --help should only show how to alter the default behaviour. Thus not articulating explicitly the default on --help, implies that not passing an option to ./configure will not imply that option. See also my article https://ab.bapha.be/posts/help-output/.

With Python 3.15.3 ./configure --help:

  --enable-universalsdk[=SDKDIR]
                          create a universal binary build. SDKDIR specifies
                          which macOS SDK should be used to perform the build,
                          see Mac/README.rst. (default is no)
  --enable-framework[=INSTALLDIR]
                          create a Python.framework rather than a traditional
                          Unix install. optional INSTALLDIR specifies the
                          installation path. see Mac/README.rst (default is
                          no)
  --enable-wasm-dynamic-linking
                          Enable dynamic linking support for WebAssembly
                          (default is no)
  --enable-wasm-pthreads  Enable pthread emulation for WebAssembly (default is
                          no)
  --enable-shared         enable building a shared Python library (default is
                          no)
  --enable-profiling      enable C-level code profiling with gprof (default is
                          no)
  --disable-gil           enable experimental support for running without the
                          GIL (default is no)
  --enable-pystats        enable internal statistics gathering (default is no)
  --enable-optimizations  enable expensive, stable optimizations (PGO, etc.)
                          (default is no)
  --enable-bolt           enable usage of the llvm-bolt post-link optimizer
                          (default is no)
  --enable-loadable-sqlite-extensions
                          support loadable extensions in the sqlite3 module,
                          see Doc/library/sqlite3.rst (default is no)
  --disable-test-modules  don't build nor install test modules
  --without-static-libpython
                          do not build libpythonMAJOR.MINOR.a and do not
                          install python.o (default is yes)

and more…

--disable-test-modules is used as I suggested. --disable-gil should be renamed to --enable-gil. All (default is no) and (default is yes) should be removed, when the option is binary (on/off/yes/no/with/without/enabled/disabled).

When a parameter has many possible values, sometimes --help emits =[ and sometimes [=. This is inconsistent:

  --enable-big-digits[=15|30]
                          use big digits (30 or 15 bits) for Python longs
                          (default is 30)]
  --with-pkg-config=[yes|no|check]
                          use pkg-config to detect build options (default is
                          check)

Start by running ./configure --help and compare the documented binary defaults and parameter syntax with the examples in this issue and the linked article. Locate the configuration-help definitions that produce these entries, then verify that default annotations are omitted for binary options and value syntax is consistent. Done means the generated help output follows the requested wording and remains accurate.