Closed as not planned
Description
Feature or enhancement
Proposal:
Python 3.12 changed the default for Clang to ThinLTO. However, many people were unaware of this change and did not update their build scripts. This leaves a lot of perf on the table for macOS and possibly some other platforms.
- CPython was bitten by this: Python3.13 performance Issue with python.org macOS installers on ARM Macs #122580
- Faster CPython was bitten by this: clang builds not using full LTO faster-cpython/bench_runner#342
- python-build-standalone (Astral) also seems to not have the fix: On Clang, LTO is ThinLTO, which leaves a lot of performance out for macOS astral-sh/python-build-standalone#528
- msys2/mingw also seems to have not noticed: python: build with full lto msys2/MINGW-packages#23384
This seems to be confusing and tripping up a lot of people. I propose we change the --with-lto
default back to full.
Has this already been discussed elsewhere?
No response given
Links to previous discussion of this feature:
No response