BUG: fix a bug where calling distutils.build_ext.finalize_options after define or undef attributes were set raised an exception#5084

neutrinoceros wants to merge 1 commit intopypa:mainpypa/setuptools:mainfrom

neutrinoceros:enh/build-ext-finalize-options-idempotency-defundefneutrinoceros/setuptools:enh/build-ext-finalize-options-idempotency-defundefCopy head branch name to clipboard