Remove support for Linux x86 builds

cpython-unix/base.Dockerfile

@@ -29,10 +29,6 @@ RUN for s in debian_jessie debian_jessie-updates debian-security_jessie/updates;
       echo 'Acquire::Retries "5";'; \
     ) > /etc/apt/apt.conf.d/99cpython-portable
 
-RUN ( echo 'amd64'; \
-      echo 'i386'; \
-    ) > /var/lib/dpkg/arch
-
 # apt iterates all available file descriptors up to rlim_max and calls
 # fcntl(fd, F_SETFD, FD_CLOEXEC). This can result in millions of system calls
 # (we've seen 1B in the wild) and cause operations to take seconds to minutes.

cpython-unix/build-cpython.sh

@@ -91,6 +91,9 @@ fi
 
 # Configure nerfs RUNSHARED when cross-compiling, which prevents PGO from running when
 # we can in fact run the target binaries (e.g. x86_64 host and i686 target). Undo that.
+# TODO this may not be needed after removing support for i686 builds. But it
+# may still be useful since CPython's definition of cross-compiling has historically
+# been very liberal and kicks in when it arguably shouldn't.
 if [ -n "${CROSS_COMPILING}" ]; then
     if [ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_14}" ]; then
         patch -p1 -i ${ROOT}/patch-dont-clear-runshared-14.patch
@@ -1058,9 +1061,6 @@ armv7-unknown-linux-gnueabi)
 armv7-unknown-linux-gnueabihf)
     PYTHON_ARCH="arm-linux-gnueabihf"
     ;;
-i686-unknown-linux-gnu)
-    PYTHON_ARCH="i386-linux-gnu"
-    ;;
 mips-unknown-linux-gnu)
     PYTHON_ARCH="mips-linux-gnu"
     ;;

cpython-unix/build-libX11.sh

@@ -54,9 +54,6 @@ if [ -n "${CROSS_COMPILING}" ]; then
     armv7-unknown-linux-gnueabihf)
       EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
       ;;
-    i686-unknown-linux-gnu)
-      EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
-      ;;
     mips-unknown-linux-gnu)
       EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
       ;;
@@ -81,9 +78,6 @@ if [ -n "${CROSS_COMPILING}" ]; then
     aarch64-unknown-linux-musl)
       EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
       ;;
-    i686-unknown-linux-musl)
-      EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
-      ;;
     mips-unknown-linux-musl)
       EXTRA_FLAGS="${EXTRA_FLAGS} --enable-malloc0returnsnull"
       ;;

cpython-unix/build.Dockerfile

@@ -1,8 +1,5 @@
 {% include 'base.Dockerfile' %}
 
-# libc6-dev:i386 pulls in 32-bit system libraries to enable cross-compiling
-# to i386.
-#
 # libffi-dev and zlib1g-dev are present so host Python (during cross-builds)
 # can build the ctypes and zlib extensions. So comment in build-cpython.sh
 # for more context.
@@ -14,7 +11,6 @@ RUN ulimit -n 10000 && apt-get install \
     bzip2 \
     file \
     libc6-dev \
-    libc6-dev:i386 \
     libffi-dev \
     make \
     patch \

cpython-unix/extension-modules.yml

@@ -249,7 +249,6 @@ _decimal:
     - define: CONFIG_32=1
       targets:
         - armv7-.*
-        - i686-.*
         - mips-.*
         - mipsel-.*
     - define: CONFIG_64=1
@@ -299,7 +298,6 @@ _hashlib:
     # a static library so there isn't a runtime dependency.
     - name: ':libatomic.a'
       targets:
-        - i686-unknown-linux-gnu
         - mips-unknown-linux-gnu
         - mipsel-unknown-linux-gnu
         - x86_64.*-unknown-linux-gnu
@@ -570,7 +568,6 @@ _ssl:
     # a static library so there isn't a runtime dependency.
     - name: ':libatomic.a'
       targets:
-        - i686-unknown-linux-gnu
         - mips-unknown-linux-gnu
         - mipsel-unknown-linux-gnu
         - x86_64.*-unknown-linux-gnu

cpython-unix/targets.yml

@@ -318,52 +318,6 @@ armv7-unknown-linux-gnueabihf:
     - zlib
   openssl_target: linux-armv4
 
-i686-unknown-linux-gnu:
-  host_platforms:
-    - linux_x86_64
-  pythons_supported:
-    - '3.9'
-    - '3.10'
-    - '3.11'
-    - '3.12'
-    - '3.13'
-    - '3.14'
-  needs_toolchain: true
-  host_cc: clang
-  host_cxx: clang++
-  target_cc: clang
-  target_cxx: clang++
-  target_cflags:
-    - '-m32'
-    - '-fvisibility=hidden'
-  target_ldflags:
-    - '-m32'
-  needs:
-    - autoconf
-    - bdb
-    - binutils
-    - bzip2
-    - expat
-    - libedit
-    - libffi
-    - libX11
-    - libXau
-    - libxcb
-    - m4
-    - mpdecimal
-    - ncurses
-    - openssl-3.0
-    - patchelf
-    - sqlite
-    - tcl
-    - tk
-    - tix
-    - uuid
-    - xorgproto
-    - xz
-    - zlib
-  openssl_target: linux-x86-clang
-
 mips-unknown-linux-gnu:
   host_platforms:
     - linux_x86_64