The council also criticized the PEP for being overly optimistic about the performance gains to expect. Speed improvements for the CPython JIT were measurable, but small, and only improved performance for some classes of programs, such as those with long-running tight loops.
On October 19, PEP 836 was withdrawn. “The Steering Council rightly sets a high bar for a proposal of this scope, and we don’t feel we have the personal bandwidth to carry the current version forward,” Ostrowski said. “We continue to believe in the technical direction outlined in the PEP, including free-threaded support and a method-based front end, and remain optimistic about the JIT’s potential in CPython.”
Nothing forbids other developers from continuing where the JIT project left off. Withdrawing PEP 836 simply means that work on the JIT in the mainline edition of CPython won’t go forward. Other developers are free to continue the work in their own way, perhaps in an alternative build of CPython, although they will face the same high bar if they want to contribute that work back to CPython.
