DNM: enable the experimental JIT in 3.13+

Author: tianon

3.13/bookworm/Dockerfile

@@ -96,6 +96,8 @@ ENV PYTHON_SHA256 {{ .checksums.source.sha256 }}
 
 RUN set -eux; \
 	\
+{{ # https://github.com/python/cpython/blob/3.13/Tools/jit/README.md -}}
+{{ def llvmVersion: if rcVersion == "3.13" then "18" else "19" end -}}
 {{ if is_alpine then ( -}}
 	apk add --no-cache --virtual .build-deps \
 		gnupg \
@@ -151,6 +153,12 @@ RUN set -eux; \
 		wget \
 		xz-utils \
 		zlib1g-dev \
+{{ if IN(rcVersion; "3.9", "3.10", "3.11", "3.12") then "" else ( -}}
+# hack hack hack: https://github.com/python/cpython/blob/3.13/Tools/jit/README.md
+		clang-{{ llvmVersion }} \
+		llvm-{{ llvmVersion }} \
+		python3 \
+{{ ) end -}}
 	; \
 	\
 {{ ) else "" end -}}
@@ -192,6 +200,11 @@ RUN set -eux; \
 		$(test "${gnuArch%%-*}" != 'riscv64' && echo '--with-lto') \
 {{ ) end -}}
 		--with-ensurepip \
+{{ if IN(rcVersion; "3.9", "3.10", "3.11", "3.12") or is_alpine then "" else ( -}}
+# https://github.com/docker-library/python/issues/947
+# https://docs.python.org/3.14/whatsnew/3.14.html#binary-releases-for-the-experimental-just-in-time-compiler
+		--enable-experimental-jit=yes-off \
+{{ ) end -}}
 	; \
 	nproc="$(nproc)"; \
 {{ if is_alpine then ( -}}