diff --git a/3.11/alpine3.23/Dockerfile b/3.11/alpine3.23/Dockerfile
index 21fd4c70c..517c5c645 100644
--- a/3.11/alpine3.23/Dockerfile
+++ b/3.11/alpine3.23/Dockerfile
@@ -10,8 +10,12 @@ FROM alpine:3.23
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.11 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.11/alpine3.24/Dockerfile b/3.11/alpine3.24/Dockerfile
index 76e41d417..2d9b4c568 100644
--- a/3.11/alpine3.24/Dockerfile
+++ b/3.11/alpine3.24/Dockerfile
@@ -10,8 +10,12 @@ FROM alpine:3.24
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.11 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.11/bookworm/Dockerfile b/3.11/bookworm/Dockerfile
index 106e28002..d5007a081 100644
--- a/3.11/bookworm/Dockerfile
+++ b/3.11/bookworm/Dockerfile
@@ -10,8 +10,12 @@ FROM buildpack-deps:bookworm
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.11 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.11/slim-bookworm/Dockerfile b/3.11/slim-bookworm/Dockerfile
index 6fc35c4d5..7b5f38efc 100644
--- a/3.11/slim-bookworm/Dockerfile
+++ b/3.11/slim-bookworm/Dockerfile
@@ -10,8 +10,12 @@ FROM debian:bookworm-slim
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.11 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.11/slim-trixie/Dockerfile b/3.11/slim-trixie/Dockerfile
index 3629f7644..d480e5e51 100644
--- a/3.11/slim-trixie/Dockerfile
+++ b/3.11/slim-trixie/Dockerfile
@@ -10,8 +10,12 @@ FROM debian:trixie-slim
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.11 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.11/trixie/Dockerfile b/3.11/trixie/Dockerfile
index d90fb640a..3d4ae0d23 100644
--- a/3.11/trixie/Dockerfile
+++ b/3.11/trixie/Dockerfile
@@ -10,8 +10,12 @@ FROM buildpack-deps:trixie
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.11 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.12/alpine3.23/Dockerfile b/3.12/alpine3.23/Dockerfile
index 0379fb14b..7e9434031 100644
--- a/3.12/alpine3.23/Dockerfile
+++ b/3.12/alpine3.23/Dockerfile
@@ -10,8 +10,12 @@ FROM alpine:3.23
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.12 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.12/alpine3.24/Dockerfile b/3.12/alpine3.24/Dockerfile
index 9470bbab6..66b4e977e 100644
--- a/3.12/alpine3.24/Dockerfile
+++ b/3.12/alpine3.24/Dockerfile
@@ -10,8 +10,12 @@ FROM alpine:3.24
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.12 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.12/bookworm/Dockerfile b/3.12/bookworm/Dockerfile
index a580001dd..77161177a 100644
--- a/3.12/bookworm/Dockerfile
+++ b/3.12/bookworm/Dockerfile
@@ -10,8 +10,12 @@ FROM buildpack-deps:bookworm
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.12 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.12/slim-bookworm/Dockerfile b/3.12/slim-bookworm/Dockerfile
index 0658ea6df..474bb4d25 100644
--- a/3.12/slim-bookworm/Dockerfile
+++ b/3.12/slim-bookworm/Dockerfile
@@ -10,8 +10,12 @@ FROM debian:bookworm-slim
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.12 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.12/slim-trixie/Dockerfile b/3.12/slim-trixie/Dockerfile
index b184625b8..6851c2efc 100644
--- a/3.12/slim-trixie/Dockerfile
+++ b/3.12/slim-trixie/Dockerfile
@@ -10,8 +10,12 @@ FROM debian:trixie-slim
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.12 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.12/trixie/Dockerfile b/3.12/trixie/Dockerfile
index 409c1452c..fef58139b 100644
--- a/3.12/trixie/Dockerfile
+++ b/3.12/trixie/Dockerfile
@@ -10,8 +10,12 @@ FROM buildpack-deps:trixie
 ENV PATH /usr/local/bin:$PATH
 
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.12 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
 # runtime dependencies
diff --git a/3.13/alpine3.23/Dockerfile b/3.13/alpine3.23/Dockerfile
index 424eb6f9d..c88143d9f 100644
--- a/3.13/alpine3.23/Dockerfile
+++ b/3.13/alpine3.23/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.23
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.13 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.13/alpine3.24/Dockerfile b/3.13/alpine3.24/Dockerfile
index 14788257f..720a773fa 100644
--- a/3.13/alpine3.24/Dockerfile
+++ b/3.13/alpine3.24/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.24
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.13 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.13/bookworm/Dockerfile b/3.13/bookworm/Dockerfile
index 0152e0195..4c7599475 100644
--- a/3.13/bookworm/Dockerfile
+++ b/3.13/bookworm/Dockerfile
@@ -9,6 +9,15 @@ FROM buildpack-deps:bookworm
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.13 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.13/slim-bookworm/Dockerfile b/3.13/slim-bookworm/Dockerfile
index 046330be9..6bbeaea52 100644
--- a/3.13/slim-bookworm/Dockerfile
+++ b/3.13/slim-bookworm/Dockerfile
@@ -9,6 +9,15 @@ FROM debian:bookworm-slim
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.13 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.13/slim-trixie/Dockerfile b/3.13/slim-trixie/Dockerfile
index f32081f1c..aa37cc9a5 100644
--- a/3.13/slim-trixie/Dockerfile
+++ b/3.13/slim-trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM debian:trixie-slim
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.13 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.13/trixie/Dockerfile b/3.13/trixie/Dockerfile
index eaf1e181c..342902cd4 100644
--- a/3.13/trixie/Dockerfile
+++ b/3.13/trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM buildpack-deps:trixie
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.13 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.14/alpine3.23/Dockerfile b/3.14/alpine3.23/Dockerfile
index fcbccaa81..698552738 100644
--- a/3.14/alpine3.23/Dockerfile
+++ b/3.14/alpine3.23/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.23
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.14 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.14/alpine3.24/Dockerfile b/3.14/alpine3.24/Dockerfile
index 50bdfb6ff..9e740e194 100644
--- a/3.14/alpine3.24/Dockerfile
+++ b/3.14/alpine3.24/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.24
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.14 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.14/bookworm/Dockerfile b/3.14/bookworm/Dockerfile
index df08d2388..9b454c937 100644
--- a/3.14/bookworm/Dockerfile
+++ b/3.14/bookworm/Dockerfile
@@ -9,6 +9,15 @@ FROM buildpack-deps:bookworm
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.14 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.14/slim-bookworm/Dockerfile b/3.14/slim-bookworm/Dockerfile
index 39192728d..ac87e18f3 100644
--- a/3.14/slim-bookworm/Dockerfile
+++ b/3.14/slim-bookworm/Dockerfile
@@ -9,6 +9,15 @@ FROM debian:bookworm-slim
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.14 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.14/slim-trixie/Dockerfile b/3.14/slim-trixie/Dockerfile
index 7425a1e18..6538b57b7 100644
--- a/3.14/slim-trixie/Dockerfile
+++ b/3.14/slim-trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM debian:trixie-slim
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.14 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.14/trixie/Dockerfile b/3.14/trixie/Dockerfile
index 492e66405..9646b9b48 100644
--- a/3.14/trixie/Dockerfile
+++ b/3.14/trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM buildpack-deps:trixie
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.14 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.15/alpine3.23/Dockerfile b/3.15/alpine3.23/Dockerfile
index 7544dec24..1d917edc0 100644
--- a/3.15/alpine3.23/Dockerfile
+++ b/3.15/alpine3.23/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.23
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.15 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.15/alpine3.24/Dockerfile b/3.15/alpine3.24/Dockerfile
index daad35628..da1d2dfc8 100644
--- a/3.15/alpine3.24/Dockerfile
+++ b/3.15/alpine3.24/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.24
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.15 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.15/bookworm/Dockerfile b/3.15/bookworm/Dockerfile
index 9428aad02..f002847e0 100644
--- a/3.15/bookworm/Dockerfile
+++ b/3.15/bookworm/Dockerfile
@@ -9,6 +9,15 @@ FROM buildpack-deps:bookworm
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.15 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.15/slim-bookworm/Dockerfile b/3.15/slim-bookworm/Dockerfile
index f9bc43c52..22bbd6542 100644
--- a/3.15/slim-bookworm/Dockerfile
+++ b/3.15/slim-bookworm/Dockerfile
@@ -9,6 +9,15 @@ FROM debian:bookworm-slim
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.15 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.15/slim-trixie/Dockerfile b/3.15/slim-trixie/Dockerfile
index 409e58c59..3d9576a9b 100644
--- a/3.15/slim-trixie/Dockerfile
+++ b/3.15/slim-trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM debian:trixie-slim
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.15 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.15/trixie/Dockerfile b/3.15/trixie/Dockerfile
index 525464355..1768537cb 100644
--- a/3.15/trixie/Dockerfile
+++ b/3.15/trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM buildpack-deps:trixie
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.15 sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.16-rc/alpine3.23/Dockerfile b/3.16-rc/alpine3.23/Dockerfile
index 935da0f4b..bda64853b 100644
--- a/3.16-rc/alpine3.23/Dockerfile
+++ b/3.16-rc/alpine3.23/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.23
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.16-rc sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.16-rc/alpine3.24/Dockerfile b/3.16-rc/alpine3.24/Dockerfile
index b9a7af65d..25fbda7ce 100644
--- a/3.16-rc/alpine3.24/Dockerfile
+++ b/3.16-rc/alpine3.24/Dockerfile
@@ -9,6 +9,15 @@ FROM alpine:3.24
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.16-rc sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apk add --no-cache \
diff --git a/3.16-rc/slim-trixie/Dockerfile b/3.16-rc/slim-trixie/Dockerfile
index 8dca73628..96a241639 100644
--- a/3.16-rc/slim-trixie/Dockerfile
+++ b/3.16-rc/slim-trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM debian:trixie-slim
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.16-rc sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/3.16-rc/trixie/Dockerfile b/3.16-rc/trixie/Dockerfile
index 45055a827..66264ac4e 100644
--- a/3.16-rc/trixie/Dockerfile
+++ b/3.16-rc/trixie/Dockerfile
@@ -9,6 +9,15 @@ FROM buildpack-deps:trixie
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
+# cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
+# last attempted removal of LANG broke many users:
+# https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:3.16-rc sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
+ENV LANG C.UTF-8
+
 # runtime dependencies
 RUN set -eux; \
 	apt-get update; \
diff --git a/Dockerfile-linux.template b/Dockerfile-linux.template
index f95548890..2509ecddb 100644
--- a/Dockerfile-linux.template
+++ b/Dockerfile-linux.template
@@ -25,14 +25,15 @@ FROM buildpack-deps:{{ env.variant }}
 # ensure local python is preferred over distribution python
 ENV PATH /usr/local/bin:$PATH
 
-{{ if rcVersion | IN("3.11", "3.12") then ( -}}
-{{ # only set LANG on versions less than 3.13 -}}
 # cannot remove LANG even though https://bugs.python.org/issue19846 is fixed
+# - embedded interpreters (uWSGI, mod_wsgi, etc) skip locale coercion and UTF-8 mode before Python 3.15, so they fall back to ASCII
+# - musl (alpine) never gets LC_CTYPE set, so anything that reads locale environment variables (babel) finds none
 # last attempted removal of LANG broke many users:
 # https://github.com/docker-library/python/pull/570
+# embedded interpreter reproducer (fails with UnicodeEncodeError without LANG on 3.14 and earlier, needs a non-slim Debian variant for gcc):
+# docker run --rm --env LANG= python:{{ env.version }} sh -c 'printf "#include <Python.h>\nint main(){Py_Initialize();PyRun_SimpleString(\"print(chr(252),flush=True)\");}" | gcc -x c - $(python3-config --embed --cflags --ldflags) && ./a.out'
 ENV LANG C.UTF-8
 
-{{ ) else "" end -}}
 # runtime dependencies
 {{ if is_alpine then ( -}}
 RUN set -eux; \