From a5d1f4195cda9fdc45c730c628d4ee49c825f210 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 17:53:55 +0000
Subject: [PATCH 01/25] maint: add Windows on ARM64 support

---
 .github/workflows/buildwheel.yml              | 13 ++++++++++--
 ...ws.sh => cibw_before_all_windows_amd64.sh} |  0
 bin/cibw_before_all_windows_arm64.sh          | 20 +++++++++++++++++++
 3 files changed, 31 insertions(+), 2 deletions(-)
 rename bin/{cibw_before_all_windows.sh => cibw_before_all_windows_amd64.sh} (100%)
 create mode 100755 bin/cibw_before_all_windows_arm64.sh

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index 9b48d669..3c87f6dc 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -10,7 +10,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-22.04, ubuntu-22.04-arm, windows-2022, macos-15-intel, macos-14]
+        os: [
+          ubuntu-22.04,
+          ubuntu-22.04-arm,
+          windows-2022,
+          windows-11-arm,
+          macos-15-intel,
+          macos-14,
+        ]
 
     steps:
       - uses: actions/checkout@v6.0.1
@@ -38,7 +45,8 @@ jobs:
         uses: pypa/cibuildwheel@63fd63b352a9a8bdcc24791c9dbee952ee9a8abc # v3.3.0
         env:
           # override setting in pyproject.toml to use msys2 instead of msys64 bash
-          CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows.sh
+          CIBW_BEFORE_ALL_WINDOWS_AMD64: msys2 -c bin/cibw_before_all_windows_amd64.sh
+          CIBW_BEFORE_ALL_WINDOWS_ARM64: msys2 -c bin/cibw_before_all_windows_arm64.sh
 
       - uses: actions/upload-artifact@v5
         with:
@@ -78,6 +86,7 @@ jobs:
           ubuntu-24.04-arm,
           windows-2022,
           windows-2025,
+          windows-11-arm,
           macos-15-intel,
           macos-14,
           macos-15,
diff --git a/bin/cibw_before_all_windows.sh b/bin/cibw_before_all_windows_amd64.sh
similarity index 100%
rename from bin/cibw_before_all_windows.sh
rename to bin/cibw_before_all_windows_amd64.sh
diff --git a/bin/cibw_before_all_windows_arm64.sh b/bin/cibw_before_all_windows_arm64.sh
new file mode 100755
index 00000000..5db3dfb1
--- /dev/null
+++ b/bin/cibw_before_all_windows_arm64.sh
@@ -0,0 +1,20 @@
+#!/bin/bash
+
+set -o errexit
+
+pacman -S --noconfirm \
+    mingw-w64-clang-aarch64-toolchain\
+    mingw-w64-clang-aarch64-tools-git\
+    m4\
+    make\
+    base-devel\
+    autoconf-wrapper\
+    automake-wrapper\
+    libtool\
+    git\
+    #
+
+bin/build_dependencies_unix.sh \
+    --use-gmp-github-mirror\
+    --patch-C23\
+    #

From 0606e709bbb8bb4c6ae744bbd517377adb309fd6 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 18:17:26 +0000
Subject: [PATCH 02/25] Fix env var names in buildwheel.yml

---
 .github/workflows/buildwheel.yml | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index 3c87f6dc..212d6164 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -41,12 +41,29 @@ jobs:
       - run: echo "PKG_CONFIG_PATH=${{ github.workspace }}/.local/lib/pkgconfig" >> $env:GITHUB_ENV
         if: ${{ startsWith( matrix.os , 'windows' ) }}
 
-      - name: Build wheels
+        # We need to set these environment variables here rather than
+        # pyproject.toml so we can use differnt values for different
+        # architectures. For non-Windows this is just done with $(uname -m)
+        # don't know what that would do in msys2 on Windows when cibuildwheel
+        # parses it.
+
+      - name: Build wheels for windows-2022
+        uses: pypa/cibuildwheel@63fd63b352a9a8bdcc24791c9dbee952ee9a8abc # v3.3.0
+        if: ${{ matrix.os == 'windows-2022' }}
+        env:
+          CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows_amd64.sh
+
+      - name: Build wheels for windows-11-arm
         uses: pypa/cibuildwheel@63fd63b352a9a8bdcc24791c9dbee952ee9a8abc # v3.3.0
+        if: ${{ matrix.os == 'windows-11-arm' }}
         env:
-          # override setting in pyproject.toml to use msys2 instead of msys64 bash
-          CIBW_BEFORE_ALL_WINDOWS_AMD64: msys2 -c bin/cibw_before_all_windows_amd64.sh
-          CIBW_BEFORE_ALL_WINDOWS_ARM64: msys2 -c bin/cibw_before_all_windows_arm64.sh
+          CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows_arm64.sh
+
+        # After all the Windows-specific steps above this is what actually
+        # #builds the wheels for every other OS:
+
+      - name: Build wheels for any other OS
+        uses: pypa/cibuildwheel@63fd63b352a9a8bdcc24791c9dbee952ee9a8abc # v3.3.0
 
       - uses: actions/upload-artifact@v5
         with:

From c157dc1c684651e63a47e55bea3aba94e7ecb34c Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 18:25:01 +0000
Subject: [PATCH 03/25] Set --host to arm64 for Windows on arm64

---
 bin/cibw_before_all_windows_arm64.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/bin/cibw_before_all_windows_arm64.sh b/bin/cibw_before_all_windows_arm64.sh
index 5db3dfb1..399c0ba3 100755
--- a/bin/cibw_before_all_windows_arm64.sh
+++ b/bin/cibw_before_all_windows_arm64.sh
@@ -16,5 +16,6 @@ pacman -S --noconfirm \
 
 bin/build_dependencies_unix.sh \
     --use-gmp-github-mirror\
+    --host arm64-w64-mingw32\
     --patch-C23\
     #

From 4861f0185d6d8680c543bfbae02ba48b86b5253e Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 18:40:18 +0000
Subject: [PATCH 04/25] Fix --host

---
 bin/cibw_before_all_windows_arm64.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bin/cibw_before_all_windows_arm64.sh b/bin/cibw_before_all_windows_arm64.sh
index 399c0ba3..d0f3348d 100755
--- a/bin/cibw_before_all_windows_arm64.sh
+++ b/bin/cibw_before_all_windows_arm64.sh
@@ -16,6 +16,6 @@ pacman -S --noconfirm \
 
 bin/build_dependencies_unix.sh \
     --use-gmp-github-mirror\
-    --host arm64-w64-mingw32\
+    --host aarch64-pc-windows-gnullvm\
     --patch-C23\
     #

From d2e8d0413bf3d91510fd0c58b5fbe6ece0442819 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 18:50:53 +0000
Subject: [PATCH 05/25] Use msystem = clangarm64 for windows arm64

---
 .github/workflows/buildwheel.yml     | 7 ++++++-
 bin/cibw_before_all_windows_arm64.sh | 1 -
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index 212d6164..f251c663 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -29,7 +29,12 @@ jobs:
       - uses: msys2/setup-msys2@v2.29.0
         with:
           msystem: mingw64
-        if: ${{ startsWith( matrix.os , 'windows' ) }}
+        if: ${{ matrix.os == 'windows-2022' }}
+
+      - uses: msys2/setup-msys2@v2.29.0
+        with:
+          msystem: clangarm64
+        if: ${{ matrix.os == 'windows-11-arm' }}
 
         # Install pkgconfig on Windows from choco rather than from msys and
         # avoid using the Strawberry one.
diff --git a/bin/cibw_before_all_windows_arm64.sh b/bin/cibw_before_all_windows_arm64.sh
index d0f3348d..5db3dfb1 100755
--- a/bin/cibw_before_all_windows_arm64.sh
+++ b/bin/cibw_before_all_windows_arm64.sh
@@ -16,6 +16,5 @@ pacman -S --noconfirm \
 
 bin/build_dependencies_unix.sh \
     --use-gmp-github-mirror\
-    --host aarch64-pc-windows-gnullvm\
     --patch-C23\
     #

From 49291df89435c0f1799427fd359ec586731b7ee4 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 19:04:32 +0000
Subject: [PATCH 06/25] Don't run cibuildwheel twice on Windows

---
 .github/workflows/buildwheel.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index f251c663..edb3d42b 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -65,10 +65,11 @@ jobs:
           CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows_arm64.sh
 
         # After all the Windows-specific steps above this is what actually
-        # #builds the wheels for every other OS:
+        # builds the wheels for every other OS:
 
       - name: Build wheels for any other OS
         uses: pypa/cibuildwheel@63fd63b352a9a8bdcc24791c9dbee952ee9a8abc # v3.3.0
+        if: ${{ !startsWith( matrix.os , 'windows' ) }}
 
       - uses: actions/upload-artifact@v5
         with:

From a7be3bf0fc73fe0ca889c827b2b14a612f6c5a7d Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 19:43:56 +0000
Subject: [PATCH 07/25] Don't use fat build for Windows on ARM64

---
 bin/build_dependencies_unix.sh       | 9 ++++++++-
 bin/cibw_before_all_windows_arm64.sh | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/bin/build_dependencies_unix.sh b/bin/build_dependencies_unix.sh
index 6dfdeb12..184da108 100755
--- a/bin/build_dependencies_unix.sh
+++ b/bin/build_dependencies_unix.sh
@@ -18,6 +18,7 @@ set -o errexit
 
 SKIP_GMP=no
 SKIP_MPFR=no
+FAT_GMP_ARG="--enable-fat"
 
 USE_GMP=gmp
 PATCH_GMP_ARM64=no
@@ -37,6 +38,7 @@ do
       echo "  --host <HOST>     - set the host (target) for GMP build"
       echo "  --skip-gmp        - skip building GMP"
       echo "  --skip-mpfr       - skip building MPFR"
+      echo "  --disable-fat     - disable building fat binaries"
       echo
       echo "Legacy options:"
       echo "  --gmp gmp         - build based on GMP (default)"
@@ -83,6 +85,11 @@ do
       SKIP_MPFR=yes
       shift
     ;;
+    --disable-fat)
+      # Disable building fat binaries
+      FAT_GMP_ARG="--disable-assembly"
+      shift
+    ;;
     --patch-gmp-arm64)
       # Needed only for GMP 6.2.1 on OSX arm64 (Apple M1) hardware
       # As of GMP 6.3.0 this patch is no longer needed
@@ -190,7 +197,7 @@ if [ $USE_GMP = "gmp" ]; then
       ./configfsf.guess
 
       ./configure --prefix=$PREFIX\
-        --enable-fat\
+        $FAT_GMP_ARG\
         --enable-shared=yes\
         --enable-static=no\
         --host=$HOST_ARG
diff --git a/bin/cibw_before_all_windows_arm64.sh b/bin/cibw_before_all_windows_arm64.sh
index 5db3dfb1..3aae38b5 100755
--- a/bin/cibw_before_all_windows_arm64.sh
+++ b/bin/cibw_before_all_windows_arm64.sh
@@ -15,6 +15,7 @@ pacman -S --noconfirm \
     #
 
 bin/build_dependencies_unix.sh \
+    --disable-fat\
     --use-gmp-github-mirror\
     --patch-C23\
     #

From fcb49d2e2f0f300842811c14e24bbccb4f4b536d Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 20:56:13 +0000
Subject: [PATCH 08/25] Patch FLINT for mingw on arm64

---
 bin/build_dependencies_unix.sh       | 16 ++++++++
 bin/cibw_before_all_windows_arm64.sh |  1 +
 bin/patch-ldd.diff                   | 59 ++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+)
 create mode 100644 bin/patch-ldd.diff

diff --git a/bin/build_dependencies_unix.sh b/bin/build_dependencies_unix.sh
index 184da108..d203e2d5 100755
--- a/bin/build_dependencies_unix.sh
+++ b/bin/build_dependencies_unix.sh
@@ -19,6 +19,7 @@ set -o errexit
 SKIP_GMP=no
 SKIP_MPFR=no
 FAT_GMP_ARG="--enable-fat"
+PATCH_LDD=no
 
 USE_GMP=gmp
 PATCH_GMP_ARM64=no
@@ -39,6 +40,7 @@ do
       echo "  --skip-gmp        - skip building GMP"
       echo "  --skip-mpfr       - skip building MPFR"
       echo "  --disable-fat     - disable building fat binaries"
+      echo "  --patch-ldd       - patch flint to work with ldd (for mingw on arm64)"
       echo
       echo "Legacy options:"
       echo "  --gmp gmp         - build based on GMP (default)"
@@ -101,6 +103,11 @@ do
       PATCH_GMP_C23=yes
       shift
     ;;
+    --patch-ldd)
+      # Needed only for GMP 6.3.0 on OSX arm64 (Apple M1) hardware
+      PATCH_LDD=yes
+      shift
+    ;;
     --use-gmp-github-mirror)
       USE_GMP_GITHUB_MIRROR=yes
       shift
@@ -316,6 +323,15 @@ echo
 curl -O -L https://github.com/flintlib/flint/releases/download/v$FLINTVER/flint-$FLINTVER.tar.gz
 tar xf flint-$FLINTVER.tar.gz
 cd flint-$FLINTVER
+
+  if [ $PATCH_LDD = "yes" ]; then
+    echo
+    echo --------------------------------------------
+    echo "           patching FLINT"
+    echo --------------------------------------------
+    patch -N -Z -p0 < ../../../bin/patch-ldd.diff
+  fi
+
   ./bootstrap.sh
   ./configure --prefix=$PREFIX\
     --host=$HOST_ARG\
diff --git a/bin/cibw_before_all_windows_arm64.sh b/bin/cibw_before_all_windows_arm64.sh
index 3aae38b5..01c38ced 100755
--- a/bin/cibw_before_all_windows_arm64.sh
+++ b/bin/cibw_before_all_windows_arm64.sh
@@ -18,4 +18,5 @@ bin/build_dependencies_unix.sh \
     --disable-fat\
     --use-gmp-github-mirror\
     --patch-C23\
+    --patch-ldd\
     #
diff --git a/bin/patch-ldd.diff b/bin/patch-ldd.diff
new file mode 100644
index 00000000..df2fb955
--- /dev/null
+++ b/bin/patch-ldd.diff
@@ -0,0 +1,59 @@
+diff --git a/Makefile.in b/Makefile.in
+index 0f25aa2b5..cc0e44708 100644
+--- a/Makefile.in
++++ b/Makefile.in
+@@ -416,6 +416,10 @@ endif
+ ifneq ($(SHARED), 0)
+ shared: $(FLINT_DIR)/$(FLINT_LIB_FULL)
+ 
++ifneq ($(strip $(filter gnu% linux-gnu%,@FLINT_BUILD_OS@)),)
++# No command line length limitations under build_os=gnu*|linux-gnu*
++MERGED_OBJS := $(foreach dir,$(DIRS),$($(dir)_OBJS))
++else
+ # The following is to avoid reaching the maximum length of command line
+ # arguments, mainly present on MinGW.
+ define xxx_merged_lobj_rule
+@@ -424,6 +428,7 @@ $(BUILD_DIR)/$(1)_merged.lo: $($(1)_LOBJS) | $(BUILD_DIR)
+ endef
+ $(foreach dir, $(DIRS), $(eval $(call xxx_merged_lobj_rule,$(dir))))
+ MERGED_LOBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.lo)
++endif
+ 
+ $(FLINT_DIR)/$(FLINT_LIB_FULL): $(MERGED_LOBJS)
+ 	@echo "Building $(FLINT_LIB_FULL)"
+@@ -437,6 +442,10 @@ endif
+ ifneq ($(STATIC), 0)
+ static: $(FLINT_DIR)/$(FLINT_LIB_STATIC)
+ 
++ifneq ($(strip $(filter gnu% linux-gnu%,@FLINT_BUILD_OS@)),)
++# No command line length limitations under build_os=gnu*|linux-gnu*
++MERGED_OBJS := $(foreach dir,$(DIRS),$($(dir)_OBJS))
++else
+ # The following is to avoid reaching the maximum length of command line
+ # arguments, mainly present on MinGW.
+ define xxx_merged_obj_rule
+@@ -445,6 +454,7 @@ $(BUILD_DIR)/$(1)_merged.o: $($(1)_OBJS) | $(BUILD_DIR)
+ endef
+ $(foreach dir, $(DIRS), $(eval $(call xxx_merged_obj_rule,$(dir))))
+ MERGED_OBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.o)
++endif
+ 
+ $(FLINT_DIR)/$(FLINT_LIB_STATIC): $(MERGED_OBJS)
+ 	@echo "Building $(FLINT_LIB_STATIC)"
+diff --git a/configure.ac b/configure.ac
+index 511d0be9a..9f161e490 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -164,8 +164,12 @@ fi
+ 
+ dnl Get system triplet
+ dnl NOTE: This is already invoked from LT_INIT
++dnl AC_CANONICAL_BUILD
+ dnl AC_CANONICAL_HOST
+ 
++FLINT_BUILD_OS="${build_os}"
++AC_SUBST(FLINT_BUILD_OS)
++
+ ################################################################################
+ # configure headers
+ ################################################################################

From eca229b1b4b3bdf8a0dce9d24fba65881aa41974 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 21:28:37 +0000
Subject: [PATCH 09/25] Fix patch command

---
 bin/build_dependencies_unix.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bin/build_dependencies_unix.sh b/bin/build_dependencies_unix.sh
index d203e2d5..aaec4531 100755
--- a/bin/build_dependencies_unix.sh
+++ b/bin/build_dependencies_unix.sh
@@ -329,7 +329,7 @@ cd flint-$FLINTVER
     echo --------------------------------------------
     echo "           patching FLINT"
     echo --------------------------------------------
-    patch -N -Z -p0 < ../../../bin/patch-ldd.diff
+    patch -N -Z -p1 < ../../../bin/patch-ldd.diff
   fi
 
   ./bootstrap.sh

From ad01e8374e37dc0e0dd49aff84bf396aa1b15618 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 22:38:55 +0000
Subject: [PATCH 10/25] Fix the ldd patch so that it works on Windows

---
 bin/patch-ldd.diff | 63 +++++++++++++++-------------------------------
 1 file changed, 20 insertions(+), 43 deletions(-)

diff --git a/bin/patch-ldd.diff b/bin/patch-ldd.diff
index df2fb955..718a7ac7 100644
--- a/bin/patch-ldd.diff
+++ b/bin/patch-ldd.diff
@@ -1,59 +1,36 @@
 diff --git a/Makefile.in b/Makefile.in
-index 0f25aa2b5..cc0e44708 100644
+index 0f25aa2b5..0c2f9dad9 100644
 --- a/Makefile.in
 +++ b/Makefile.in
-@@ -416,6 +416,10 @@ endif
+@@ -416,14 +416,7 @@ endif
  ifneq ($(SHARED), 0)
  shared: $(FLINT_DIR)/$(FLINT_LIB_FULL)
  
-+ifneq ($(strip $(filter gnu% linux-gnu%,@FLINT_BUILD_OS@)),)
-+# No command line length limitations under build_os=gnu*|linux-gnu*
-+MERGED_OBJS := $(foreach dir,$(DIRS),$($(dir)_OBJS))
-+else
- # The following is to avoid reaching the maximum length of command line
- # arguments, mainly present on MinGW.
- define xxx_merged_lobj_rule
-@@ -424,6 +428,7 @@ $(BUILD_DIR)/$(1)_merged.lo: $($(1)_LOBJS) | $(BUILD_DIR)
- endef
- $(foreach dir, $(DIRS), $(eval $(call xxx_merged_lobj_rule,$(dir))))
- MERGED_LOBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.lo)
-+endif
+-# The following is to avoid reaching the maximum length of command line
+-# arguments, mainly present on MinGW.
+-define xxx_merged_lobj_rule
+-$(BUILD_DIR)/$(1)_merged.lo: $($(1)_LOBJS) | $(BUILD_DIR)
+-	@$(LD) -r $($(1)_LOBJS) -o $(BUILD_DIR)/$(1)_merged.lo
+-endef
+-$(foreach dir, $(DIRS), $(eval $(call xxx_merged_lobj_rule,$(dir))))
+-MERGED_LOBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.lo)
++MERGED_LOBJS := $(foreach dir,$(DIRS),$($(dir)_OBJS))
  
  $(FLINT_DIR)/$(FLINT_LIB_FULL): $(MERGED_LOBJS)
  	@echo "Building $(FLINT_LIB_FULL)"
-@@ -437,6 +442,10 @@ endif
+@@ -437,14 +430,7 @@ endif
  ifneq ($(STATIC), 0)
  static: $(FLINT_DIR)/$(FLINT_LIB_STATIC)
  
-+ifneq ($(strip $(filter gnu% linux-gnu%,@FLINT_BUILD_OS@)),)
-+# No command line length limitations under build_os=gnu*|linux-gnu*
+-# The following is to avoid reaching the maximum length of command line
+-# arguments, mainly present on MinGW.
+-define xxx_merged_obj_rule
+-$(BUILD_DIR)/$(1)_merged.o: $($(1)_OBJS) | $(BUILD_DIR)
+-	@$(LD) -r $($(1)_OBJS) -o $(BUILD_DIR)/$(1)_merged.o
+-endef
+-$(foreach dir, $(DIRS), $(eval $(call xxx_merged_obj_rule,$(dir))))
+-MERGED_OBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.o)
 +MERGED_OBJS := $(foreach dir,$(DIRS),$($(dir)_OBJS))
-+else
- # The following is to avoid reaching the maximum length of command line
- # arguments, mainly present on MinGW.
- define xxx_merged_obj_rule
-@@ -445,6 +454,7 @@ $(BUILD_DIR)/$(1)_merged.o: $($(1)_OBJS) | $(BUILD_DIR)
- endef
- $(foreach dir, $(DIRS), $(eval $(call xxx_merged_obj_rule,$(dir))))
- MERGED_OBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.o)
-+endif
  
  $(FLINT_DIR)/$(FLINT_LIB_STATIC): $(MERGED_OBJS)
  	@echo "Building $(FLINT_LIB_STATIC)"
-diff --git a/configure.ac b/configure.ac
-index 511d0be9a..9f161e490 100644
---- a/configure.ac
-+++ b/configure.ac
-@@ -164,8 +164,12 @@ fi
- 
- dnl Get system triplet
- dnl NOTE: This is already invoked from LT_INIT
-+dnl AC_CANONICAL_BUILD
- dnl AC_CANONICAL_HOST
- 
-+FLINT_BUILD_OS="${build_os}"
-+AC_SUBST(FLINT_BUILD_OS)
-+
- ################################################################################
- # configure headers
- ################################################################################

From 91f985a679a8dfd770a2b79c663fd267c924c853 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 25 Jan 2026 23:46:50 +0000
Subject: [PATCH 11/25] Fix patch

---
 bin/patch-ldd.diff | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/bin/patch-ldd.diff b/bin/patch-ldd.diff
index 718a7ac7..81b06b92 100644
--- a/bin/patch-ldd.diff
+++ b/bin/patch-ldd.diff
@@ -1,5 +1,5 @@
 diff --git a/Makefile.in b/Makefile.in
-index 0f25aa2b5..0c2f9dad9 100644
+index 0f25aa2b5..937fffa10 100644
 --- a/Makefile.in
 +++ b/Makefile.in
 @@ -416,14 +416,7 @@ endif
@@ -14,7 +14,7 @@ index 0f25aa2b5..0c2f9dad9 100644
 -endef
 -$(foreach dir, $(DIRS), $(eval $(call xxx_merged_lobj_rule,$(dir))))
 -MERGED_LOBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.lo)
-+MERGED_LOBJS := $(foreach dir,$(DIRS),$($(dir)_OBJS))
++MERGED_LOBJS:=$(foreach dir,$(DIRS),$($(dir)_LOBJS))
  
  $(FLINT_DIR)/$(FLINT_LIB_FULL): $(MERGED_LOBJS)
  	@echo "Building $(FLINT_LIB_FULL)"
@@ -30,7 +30,7 @@ index 0f25aa2b5..0c2f9dad9 100644
 -endef
 -$(foreach dir, $(DIRS), $(eval $(call xxx_merged_obj_rule,$(dir))))
 -MERGED_OBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.o)
-+MERGED_OBJS := $(foreach dir,$(DIRS),$($(dir)_OBJS))
++MERGED_OBJS:=$(foreach dir,$(DIRS),$($(dir)_OBJS))
  
  $(FLINT_DIR)/$(FLINT_LIB_STATIC): $(MERGED_OBJS)
  	@echo "Building $(FLINT_LIB_STATIC)"

From 5ba5d339a1994ba5cb59ed10fd0ce80a1ae00b03 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sat, 21 Mar 2026 19:06:15 +0000
Subject: [PATCH 12/25] Patch FLINT's Makefile for Windows on ARM

---
 bin/build_dependencies_unix.sh          |  8 +++---
 bin/patch-flint-windows-arm64-link.diff | 27 +++++++++++++++++++
 bin/patch-ldd.diff                      | 36 -------------------------
 3 files changed, 31 insertions(+), 40 deletions(-)
 create mode 100644 bin/patch-flint-windows-arm64-link.diff
 delete mode 100644 bin/patch-ldd.diff

diff --git a/bin/build_dependencies_unix.sh b/bin/build_dependencies_unix.sh
index aaec4531..33e63184 100755
--- a/bin/build_dependencies_unix.sh
+++ b/bin/build_dependencies_unix.sh
@@ -40,7 +40,7 @@ do
       echo "  --skip-gmp        - skip building GMP"
       echo "  --skip-mpfr       - skip building MPFR"
       echo "  --disable-fat     - disable building fat binaries"
-      echo "  --patch-ldd       - patch flint to work with ldd (for mingw on arm64)"
+      echo "  --patch-ldd       - patch flint shared linking for mingw on arm64"
       echo
       echo "Legacy options:"
       echo "  --gmp gmp         - build based on GMP (default)"
@@ -104,7 +104,7 @@ do
       shift
     ;;
     --patch-ldd)
-      # Needed only for GMP 6.3.0 on OSX arm64 (Apple M1) hardware
+      # Needed only for the FLINT shared build on mingw arm64.
       PATCH_LDD=yes
       shift
     ;;
@@ -329,7 +329,7 @@ cd flint-$FLINTVER
     echo --------------------------------------------
     echo "           patching FLINT"
     echo --------------------------------------------
-    patch -N -Z -p1 < ../../../bin/patch-ldd.diff
+    patch -N -Z -p1 < ../../../bin/patch-flint-windows-arm64-link.diff
   fi
 
   ./bootstrap.sh
@@ -339,7 +339,7 @@ cd flint-$FLINTVER
     --with-mpfr=$PREFIX\
     --disable-static\
     --disable-debug
-  make -j6
+  make -j4
   make install
 cd ..
 
diff --git a/bin/patch-flint-windows-arm64-link.diff b/bin/patch-flint-windows-arm64-link.diff
new file mode 100644
index 00000000..fd77a37a
--- /dev/null
+++ b/bin/patch-flint-windows-arm64-link.diff
@@ -0,0 +1,27 @@
+diff --git a/Makefile.in b/Makefile.in
+index 0f25aa2b5..f6f46b7d6 100644
+--- a/Makefile.in
++++ b/Makefile.in
+@@ -416,14 +416,10 @@ endif
+ ifneq ($(SHARED), 0)
+ shared: $(FLINT_DIR)/$(FLINT_LIB_FULL)
+ 
+-# The following is to avoid reaching the maximum length of command line
+-# arguments, mainly present on MinGW.
+-define xxx_merged_lobj_rule
+-$(BUILD_DIR)/$(1)_merged.lo: $($(1)_LOBJS) | $(BUILD_DIR)
+-	@$(LD) -r $($(1)_LOBJS) -o $(BUILD_DIR)/$(1)_merged.lo
+-endef
+-$(foreach dir, $(DIRS), $(eval $(call xxx_merged_lobj_rule,$(dir))))
+-MERGED_LOBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.lo)
++SHARED_LINK_RSP := $(BUILD_DIR)/libflint-shared.rsp
+ 
+-$(FLINT_DIR)/$(FLINT_LIB_FULL): $(MERGED_LOBJS)
++$(FLINT_DIR)/$(FLINT_LIB_FULL): $(LOBJS) | $(BUILD_DIR)
+ 	@echo "Building $(FLINT_LIB_FULL)"
+-	@$(CC) $(CFLAGS) -shared $(EXTRA_SHARED_FLAGS) $(MERGED_LOBJS) -o $(FLINT_LIB_FULL) $(LDFLAGS) $(LIBS)
++	@: $(file >$(SHARED_LINK_RSP))$(foreach obj,$(LOBJS),$(file >>$(SHARED_LINK_RSP),$(obj)))
++	@$(CC) $(CFLAGS) -shared $(EXTRA_SHARED_FLAGS) @$(SHARED_LINK_RSP) -o $(FLINT_LIB_FULL) $(LDFLAGS) $(LIBS)
+ 	@$(RM_F) $(FLINT_LIB)
+ 	@$(RM_F) $(FLINT_LIB_MAJOR)
+ 	@$(LN_S) $(FLINT_LIB_FULL) $(FLINT_LIB)
diff --git a/bin/patch-ldd.diff b/bin/patch-ldd.diff
deleted file mode 100644
index 81b06b92..00000000
--- a/bin/patch-ldd.diff
+++ /dev/null
@@ -1,36 +0,0 @@
-diff --git a/Makefile.in b/Makefile.in
-index 0f25aa2b5..937fffa10 100644
---- a/Makefile.in
-+++ b/Makefile.in
-@@ -416,14 +416,7 @@ endif
- ifneq ($(SHARED), 0)
- shared: $(FLINT_DIR)/$(FLINT_LIB_FULL)
- 
--# The following is to avoid reaching the maximum length of command line
--# arguments, mainly present on MinGW.
--define xxx_merged_lobj_rule
--$(BUILD_DIR)/$(1)_merged.lo: $($(1)_LOBJS) | $(BUILD_DIR)
--	@$(LD) -r $($(1)_LOBJS) -o $(BUILD_DIR)/$(1)_merged.lo
--endef
--$(foreach dir, $(DIRS), $(eval $(call xxx_merged_lobj_rule,$(dir))))
--MERGED_LOBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.lo)
-+MERGED_LOBJS:=$(foreach dir,$(DIRS),$($(dir)_LOBJS))
- 
- $(FLINT_DIR)/$(FLINT_LIB_FULL): $(MERGED_LOBJS)
- 	@echo "Building $(FLINT_LIB_FULL)"
-@@ -437,14 +430,7 @@ endif
- ifneq ($(STATIC), 0)
- static: $(FLINT_DIR)/$(FLINT_LIB_STATIC)
- 
--# The following is to avoid reaching the maximum length of command line
--# arguments, mainly present on MinGW.
--define xxx_merged_obj_rule
--$(BUILD_DIR)/$(1)_merged.o: $($(1)_OBJS) | $(BUILD_DIR)
--	@$(LD) -r $($(1)_OBJS) -o $(BUILD_DIR)/$(1)_merged.o
--endef
--$(foreach dir, $(DIRS), $(eval $(call xxx_merged_obj_rule,$(dir))))
--MERGED_OBJS:=$(foreach dir, $(DIRS),$(BUILD_DIR)/$(dir)_merged.o)
-+MERGED_OBJS:=$(foreach dir,$(DIRS),$($(dir)_OBJS))
- 
- $(FLINT_DIR)/$(FLINT_LIB_STATIC): $(MERGED_OBJS)
- 	@echo "Building $(FLINT_LIB_STATIC)"

From 86b668974706217a71c78411b69b87eb25bf381f Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sat, 21 Mar 2026 19:57:58 +0000
Subject: [PATCH 13/25] Fix the malformed patch

---
 bin/patch-flint-windows-arm64-link.diff | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bin/patch-flint-windows-arm64-link.diff b/bin/patch-flint-windows-arm64-link.diff
index fd77a37a..1b67c584 100644
--- a/bin/patch-flint-windows-arm64-link.diff
+++ b/bin/patch-flint-windows-arm64-link.diff
@@ -2,7 +2,7 @@ diff --git a/Makefile.in b/Makefile.in
 index 0f25aa2b5..f6f46b7d6 100644
 --- a/Makefile.in
 +++ b/Makefile.in
-@@ -416,14 +416,10 @@ endif
+@@ -416,18 +416,12 @@ endif
  ifneq ($(SHARED), 0)
  shared: $(FLINT_DIR)/$(FLINT_LIB_FULL)
  

From f46aeddc3b8677179e82408da918031763cfeeb1 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sat, 21 Mar 2026 20:55:06 +0000
Subject: [PATCH 14/25] Don't try to link Pythonxxx.dll to extension modules

---
 meson.build | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/meson.build b/meson.build
index 16860da3..592b605e 100644
--- a/meson.build
+++ b/meson.build
@@ -18,7 +18,6 @@ cython_lower = '>=3.0.11'
 cython_upper = '<3.3'
 
 py = import('python').find_installation(pure: false)
-dep_py = py.dependency()
 
 cc = meson.get_compiler('c')
 cy = meson.get_compiler('cython')
@@ -76,7 +75,7 @@ else
   have_acb_theta = true
 endif
 
-pyflint_deps = [dep_py, gmp_dep, mpfr_dep, flint_dep]
+pyflint_deps = [gmp_dep, mpfr_dep, flint_dep]
 
 add_project_arguments(
     '-X', 'embedsignature=True',

From 42780841a45ebc0490b2b68a2356d5e088d163c5 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sat, 21 Mar 2026 22:37:45 +0000
Subject: [PATCH 15/25] Try generating the .dll.a file for clangarm64

---
 bin/cibw_before_build_windows_arm64.sh | 91 ++++++++++++++++++++++++++
 meson.build                            |  8 +++
 pyproject.toml                         |  4 ++
 3 files changed, 103 insertions(+)
 create mode 100755 bin/cibw_before_build_windows_arm64.sh

diff --git a/bin/cibw_before_build_windows_arm64.sh b/bin/cibw_before_build_windows_arm64.sh
new file mode 100755
index 00000000..128698f5
--- /dev/null
+++ b/bin/cibw_before_build_windows_arm64.sh
@@ -0,0 +1,91 @@
+#!/bin/bash
+
+set -o errexit
+
+repo_root=$(python -c 'from pathlib import Path; print(Path.cwd().resolve().as_posix())')
+lib_dir="$repo_root/.local/lib"
+pkgconfig_dir="$lib_dir/pkgconfig"
+mkdir -p "$pkgconfig_dir"
+
+dll_name=$(python -c 'import sysconfig; print(sysconfig.get_config_var("LDLIBRARY") or "")')
+pkg_version=$(python -c 'import sysconfig; print(sysconfig.get_config_var("LDVERSION") or sysconfig.get_python_version())')
+include_dir=$(python -c 'import sysconfig; print(sysconfig.get_config_var("INCLUDEPY") or "")')
+base_prefix=$(python -c 'import sys; print(getattr(sys, "base_prefix", sys.prefix))')
+python_bin=$(python -c 'import os, sys; print(os.path.dirname(sys.executable))')
+
+include_dir=${include_dir//\\//}
+base_prefix=${base_prefix//\\//}
+python_bin=${python_bin//\\//}
+
+if [ -z "$dll_name" ] || [ -z "$include_dir" ]; then
+    echo "Could not determine Python DLL or include dir" >&2
+    exit 1
+fi
+
+dll_path=""
+for candidate in \
+    "$python_bin/$dll_name" \
+    "$base_prefix/$dll_name" \
+    "$base_prefix/DLLs/$dll_name" \
+    "$base_prefix/libs/$dll_name"
+do
+    if [ -f "$candidate" ]; then
+        dll_path="$candidate"
+        break
+    fi
+done
+
+if [ -z "$dll_path" ]; then
+    echo "Could not find $dll_name" >&2
+    exit 1
+fi
+
+if ! command -v gendef >/dev/null 2>&1; then
+    echo "Could not find gendef on PATH" >&2
+    exit 1
+fi
+
+if command -v cc >/dev/null 2>&1; then
+    dlltool=$(cc -print-prog-name=dlltool)
+fi
+if [ -n "${dlltool:-}" ] && [ -x "$dlltool" ]; then
+    :
+elif [ -n "${dlltool:-}" ] && command -v "$dlltool" >/dev/null 2>&1; then
+    dlltool=$(command -v "$dlltool")
+elif command -v dlltool >/dev/null 2>&1; then
+    dlltool=$(command -v dlltool)
+elif command -v llvm-dlltool >/dev/null 2>&1; then
+    dlltool=$(command -v llvm-dlltool)
+else
+    echo "Could not find dlltool or llvm-dlltool on PATH" >&2
+    exit 1
+fi
+
+dll_stem=${dll_name%.dll}
+def_path="$lib_dir/$dll_stem.def"
+import_lib="$lib_dir/lib$dll_stem.dll.a"
+pc_path="$pkgconfig_dir/python-$pkg_version.pc"
+
+rm -f "$def_path" "$import_lib"
+(
+    cd "$lib_dir"
+    gendef "$dll_path"
+)
+"$dlltool" -d "$def_path" -D "$dll_name" -l "$import_lib"
+
+printf 'prefix=%s\n' "$repo_root" > "$pc_path"
+printf 'exec_prefix=${prefix}\n' >> "$pc_path"
+printf 'libdir=%s\n' "$lib_dir" >> "$pc_path"
+printf 'includedir=%s\n\n' "$include_dir" >> "$pc_path"
+printf 'Name: Python\n' >> "$pc_path"
+printf 'Description: CPython import library for MinGW wheel builds\n' >> "$pc_path"
+printf 'Version: %s\n' "$pkg_version" >> "$pc_path"
+printf 'Libs: -L${libdir} -l%s\n' "$dll_stem" >> "$pc_path"
+printf 'Cflags: -I${includedir}\n' >> "$pc_path"
+
+if command -v pkg-config >/dev/null 2>&1; then
+    pkg-config --exists "python-$pkg_version"
+fi
+
+echo "Generated $import_lib"
+echo "Generated $pc_path"
diff --git a/meson.build b/meson.build
index 592b605e..6c61af96 100644
--- a/meson.build
+++ b/meson.build
@@ -77,6 +77,14 @@ endif
 
 pyflint_deps = [gmp_dep, mpfr_dep, flint_dep]
 
+# Meson's Windows sysconfig dependency path can hand the clangarm64
+# toolchain the python DLL itself. Use pkg-config on Windows ARM64 so we can
+# provide a MinGW import library instead.
+if host_machine.system() == 'windows' and host_machine.cpu_family() in ['aarch64', 'arm64'] and cc.get_id() in ['gcc', 'clang']
+  dep_py = py.dependency(method: 'pkg-config')
+  pyflint_deps = [dep_py] + pyflint_deps
+endif
+
 add_project_arguments(
     '-X', 'embedsignature=True',
     '-X', 'emit_code_comments=True',
diff --git a/pyproject.toml b/pyproject.toml
index efa88bef..6ec2b9f3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -176,3 +176,7 @@ repair-wheel-command = [
 """,
 "delvewheel repair -w {dest_dir} {wheel} --add-path .local/bin",
 ]
+
+[[tool.cibuildwheel.overrides]]
+select = ["*-win_arm64"]
+before-build = "C:\\msys64\\usr\\bin\\bash bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel"

From f089e09bd82333aa87ec92eb53c61e0c2cb9d592 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sat, 21 Mar 2026 23:25:19 +0000
Subject: [PATCH 16/25] Add .exe to commands

---
 pyproject.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pyproject.toml b/pyproject.toml
index 6ec2b9f3..ef1d9246 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -154,7 +154,7 @@ repair-wheel-command = [
 ]
 
 [tool.cibuildwheel.windows]
-before-all = "C:\\msys64\\usr\\bin\\bash bin/cibw_before_all_windows.sh"
+before-all = "C:\\msys64\\usr\\bin\\bash.exe bin/cibw_before_all_windows.sh"
 before-build = "pip install wheel delvewheel"
 repair-wheel-command = [
 """python bin/cibw_repair_wheel_licenses.py {wheel} \
@@ -179,4 +179,4 @@ repair-wheel-command = [
 
 [[tool.cibuildwheel.overrides]]
 select = ["*-win_arm64"]
-before-build = "C:\\msys64\\usr\\bin\\bash bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel"
+before-build = "C:\\msys64\\usr\\bin\\bash.exe bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel"

From 484e620a334b7d455dd453afa36d0f3d0a34a0c7 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 00:19:21 +0000
Subject: [PATCH 17/25] Move the Windows before_build command to GA yaml file

---
 .github/workflows/buildwheel.yml | 1 +
 pyproject.toml                   | 4 ----
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index 84332547..8dd81a7d 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -63,6 +63,7 @@ jobs:
         if: ${{ matrix.os == 'windows-11-arm' }}
         env:
           CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows_arm64.sh
+          CIBW_BEFORE_BUILD_WINDOWS: msys2 -c bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel
 
         # After all the Windows-specific steps above this is what actually
         # builds the wheels for every other OS:
diff --git a/pyproject.toml b/pyproject.toml
index ef1d9246..197084f8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -176,7 +176,3 @@ repair-wheel-command = [
 """,
 "delvewheel repair -w {dest_dir} {wheel} --add-path .local/bin",
 ]
-
-[[tool.cibuildwheel.overrides]]
-select = ["*-win_arm64"]
-before-build = "C:\\msys64\\usr\\bin\\bash.exe bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel"

From 4da6ab6f43e993da18b3379bd9137ee49b5feb2f Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 01:06:39 +0000
Subject: [PATCH 18/25] Simplify befre_build script for Windows on ARM

---
 .github/workflows/buildwheel.yml       |  2 +-
 bin/cibw_before_build_windows_arm64.sh | 89 +++++++++++---------------
 2 files changed, 38 insertions(+), 53 deletions(-)

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index 8dd81a7d..6373cb28 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -63,7 +63,7 @@ jobs:
         if: ${{ matrix.os == 'windows-11-arm' }}
         env:
           CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows_arm64.sh
-          CIBW_BEFORE_BUILD_WINDOWS: msys2 -c bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel
+          CIBW_BEFORE_BUILD_WINDOWS: python bin/cibw_before_build_windows_arm64.py && msys2 -c bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel
 
         # After all the Windows-specific steps above this is what actually
         # builds the wheels for every other OS:
diff --git a/bin/cibw_before_build_windows_arm64.sh b/bin/cibw_before_build_windows_arm64.sh
index 128698f5..e07e529c 100755
--- a/bin/cibw_before_build_windows_arm64.sh
+++ b/bin/cibw_before_build_windows_arm64.sh
@@ -2,49 +2,31 @@
 
 set -o errexit
 
-repo_root=$(python -c 'from pathlib import Path; print(Path.cwd().resolve().as_posix())')
-lib_dir="$repo_root/.local/lib"
-pkgconfig_dir="$lib_dir/pkgconfig"
-mkdir -p "$pkgconfig_dir"
-
-dll_name=$(python -c 'import sysconfig; print(sysconfig.get_config_var("LDLIBRARY") or "")')
-pkg_version=$(python -c 'import sysconfig; print(sysconfig.get_config_var("LDVERSION") or sysconfig.get_python_version())')
-include_dir=$(python -c 'import sysconfig; print(sysconfig.get_config_var("INCLUDEPY") or "")')
-base_prefix=$(python -c 'import sys; print(getattr(sys, "base_prefix", sys.prefix))')
-python_bin=$(python -c 'import os, sys; print(os.path.dirname(sys.executable))')
-
-include_dir=${include_dir//\\//}
-base_prefix=${base_prefix//\\//}
-python_bin=${python_bin//\\//}
-
-if [ -z "$dll_name" ] || [ -z "$include_dir" ]; then
-    echo "Could not determine Python DLL or include dir" >&2
+env_file=.local/cibw_before_build_windows_arm64.env
+if [ ! -f "$env_file" ]; then
+    echo "Could not find $env_file" >&2
     exit 1
 fi
 
-dll_path=""
-for candidate in \
-    "$python_bin/$dll_name" \
-    "$base_prefix/$dll_name" \
-    "$base_prefix/DLLs/$dll_name" \
-    "$base_prefix/libs/$dll_name"
-do
-    if [ -f "$candidate" ]; then
-        dll_path="$candidate"
-        break
-    fi
-done
+# shellcheck disable=SC1090
+. "$env_file"
 
-if [ -z "$dll_path" ]; then
-    echo "Could not find $dll_name" >&2
-    exit 1
+lib_dir_msys="$LIB_DIR"
+pkgconfig_dir_msys="$PKGCONFIG_DIR"
+dll_path_msys="$DLL_PATH"
+if command -v cygpath >/dev/null 2>&1; then
+    lib_dir_msys=$(cygpath -u "$LIB_DIR")
+    pkgconfig_dir_msys=$(cygpath -u "$PKGCONFIG_DIR")
+    dll_path_msys=$(cygpath -u "$DLL_PATH")
 fi
+mkdir -p "$pkgconfig_dir_msys"
 
 if ! command -v gendef >/dev/null 2>&1; then
     echo "Could not find gendef on PATH" >&2
     exit 1
 fi
 
+dlltool=
 if command -v cc >/dev/null 2>&1; then
     dlltool=$(cc -print-prog-name=dlltool)
 fi
@@ -61,31 +43,34 @@ else
     exit 1
 fi
 
-dll_stem=${dll_name%.dll}
-def_path="$lib_dir/$dll_stem.def"
-import_lib="$lib_dir/lib$dll_stem.dll.a"
-pc_path="$pkgconfig_dir/python-$pkg_version.pc"
+dll_stem=${DLL_NAME%.dll}
+def_path_msys="$lib_dir_msys/$dll_stem.def"
+import_lib_msys="$lib_dir_msys/lib$dll_stem.dll.a"
+pc_path_msys="$pkgconfig_dir_msys/python-$PKG_VERSION.pc"
 
-rm -f "$def_path" "$import_lib"
+rm -f "$def_path_msys" "$import_lib_msys"
 (
-    cd "$lib_dir"
-    gendef "$dll_path"
+    cd "$lib_dir_msys"
+    gendef "$dll_path_msys"
 )
-"$dlltool" -d "$def_path" -D "$dll_name" -l "$import_lib"
+"$dlltool" -d "$def_path_msys" -D "$DLL_NAME" -l "$import_lib_msys"
+
+cat > "$pc_path_msys" <<EOF
+prefix=$REPO_ROOT
+exec_prefix=\${prefix}
+libdir=$LIB_DIR
+includedir=$INCLUDE_DIR
 
-printf 'prefix=%s\n' "$repo_root" > "$pc_path"
-printf 'exec_prefix=${prefix}\n' >> "$pc_path"
-printf 'libdir=%s\n' "$lib_dir" >> "$pc_path"
-printf 'includedir=%s\n\n' "$include_dir" >> "$pc_path"
-printf 'Name: Python\n' >> "$pc_path"
-printf 'Description: CPython import library for MinGW wheel builds\n' >> "$pc_path"
-printf 'Version: %s\n' "$pkg_version" >> "$pc_path"
-printf 'Libs: -L${libdir} -l%s\n' "$dll_stem" >> "$pc_path"
-printf 'Cflags: -I${includedir}\n' >> "$pc_path"
+Name: Python
+Description: CPython import library for MinGW wheel builds
+Version: $PKG_VERSION
+Libs: -L\${libdir} -l$dll_stem
+Cflags: -I\${includedir}
+EOF
 
 if command -v pkg-config >/dev/null 2>&1; then
-    pkg-config --exists "python-$pkg_version"
+    pkg-config --exists "python-$PKG_VERSION"
 fi
 
-echo "Generated $import_lib"
-echo "Generated $pc_path"
+echo "Generated $import_lib_msys"
+echo "Generated $pc_path_msys"

From 41bab7a6656f8cc7357fdcdfb915479ed4cb04e2 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 01:42:41 +0000
Subject: [PATCH 19/25] Add the before_build script

---
 bin/cibw_before_build_windows_arm64.py | 77 ++++++++++++++++++++++++++
 1 file changed, 77 insertions(+)
 create mode 100755 bin/cibw_before_build_windows_arm64.py

diff --git a/bin/cibw_before_build_windows_arm64.py b/bin/cibw_before_build_windows_arm64.py
new file mode 100755
index 00000000..440200e9
--- /dev/null
+++ b/bin/cibw_before_build_windows_arm64.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+
+from __future__ import annotations
+
+import shlex
+import sys
+import sysconfig
+from pathlib import Path
+
+
+def _normalize_path(path: Path | str) -> str:
+    return str(path).replace('\\', '/')
+
+
+def _normalize_dll_name(name: str) -> str:
+    if name.endswith('.dll'):
+        return name
+    if name.startswith('lib') and name.endswith('.dll.a'):
+        return name[3:-2]
+    raise SystemExit(f'Unexpected Python library name: {name}')
+
+
+def _find_dll(dll_name: str) -> Path:
+    candidates: list[Path] = []
+    libdir = sysconfig.get_config_var('LIBDIR')
+    if libdir:
+        candidates.append(Path(libdir) / dll_name)
+    exe_dir = Path(sys.executable).resolve().parent
+    candidates.append(exe_dir / dll_name)
+    base_prefix = Path(getattr(sys, 'base_prefix', sys.prefix))
+    candidates.append(base_prefix / dll_name)
+    candidates.append(base_prefix / 'DLLs' / dll_name)
+    candidates.append(base_prefix / 'libs' / dll_name)
+
+    for candidate in candidates:
+        if candidate.exists():
+            return candidate.resolve()
+
+    paths = '\n'.join(_normalize_path(path) for path in candidates)
+    raise SystemExit(f'Could not find {dll_name} in:\n{paths}')
+
+
+def main() -> None:
+    repo_root = Path.cwd().resolve()
+    lib_dir = repo_root / '.local' / 'lib'
+    pkgconfig_dir = lib_dir / 'pkgconfig'
+    lib_dir.mkdir(parents=True, exist_ok=True)
+    pkgconfig_dir.mkdir(parents=True, exist_ok=True)
+
+    raw_name = sysconfig.get_config_var('DLLLIBRARY') or sysconfig.get_config_var('LDLIBRARY')
+    if not raw_name:
+        raise SystemExit('Could not determine Python DLL name')
+    dll_name = _normalize_dll_name(raw_name)
+    include_dir = sysconfig.get_config_var('INCLUDEPY')
+    if not include_dir:
+        raise SystemExit('Could not determine Python include dir')
+    pkg_version = sysconfig.get_config_var('LDVERSION') or sysconfig.get_python_version()
+    dll_path = _find_dll(dll_name)
+
+    values = {
+        'REPO_ROOT': _normalize_path(repo_root),
+        'LIB_DIR': _normalize_path(lib_dir),
+        'PKGCONFIG_DIR': _normalize_path(pkgconfig_dir),
+        'DLL_NAME': dll_name,
+        'DLL_PATH': _normalize_path(dll_path),
+        'PKG_VERSION': pkg_version,
+        'INCLUDE_DIR': _normalize_path(include_dir),
+    }
+
+    env_path = repo_root / '.local' / 'cibw_before_build_windows_arm64.env'
+    env_text = ''.join(f'{key}={shlex.quote(value)}\n' for key, value in values.items())
+    env_path.write_text(env_text, encoding='utf-8')
+    print(f'Generated {env_path}')
+
+
+if __name__ == '__main__':
+    main()

From 9f961de60328555b77b79a20a61371063eaffd87 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 02:18:24 +0000
Subject: [PATCH 20/25] Fix dll detection

---
 bin/cibw_before_build_windows_arm64.py | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/bin/cibw_before_build_windows_arm64.py b/bin/cibw_before_build_windows_arm64.py
index 440200e9..05c0f250 100755
--- a/bin/cibw_before_build_windows_arm64.py
+++ b/bin/cibw_before_build_windows_arm64.py
@@ -12,12 +12,24 @@ def _normalize_path(path: Path | str) -> str:
     return str(path).replace('\\', '/')
 
 
+def _default_dll_name() -> str:
+    vernum = sysconfig.get_config_var('py_version_nodot')
+    if not vernum:
+        vernum = f"{sys.version_info.major}{sys.version_info.minor}"
+    is_freethreaded = bool(sysconfig.get_config_var('Py_GIL_DISABLED'))
+    if not is_freethreaded:
+        abiflags = sysconfig.get_config_var('ABIFLAGS') or getattr(sys, 'abiflags', '') or ''
+        is_freethreaded = 't' in abiflags
+    suffix = 't' if is_freethreaded else ''
+    return f'python{vernum}{suffix}.dll'
+
+
 def _normalize_dll_name(name: str) -> str:
     if name.endswith('.dll'):
         return name
     if name.startswith('lib') and name.endswith('.dll.a'):
-        return name[3:-2]
-    raise SystemExit(f'Unexpected Python library name: {name}')
+        return _default_dll_name()
+    return _default_dll_name()
 
 
 def _find_dll(dll_name: str) -> Path:
@@ -47,9 +59,7 @@ def main() -> None:
     lib_dir.mkdir(parents=True, exist_ok=True)
     pkgconfig_dir.mkdir(parents=True, exist_ok=True)
 
-    raw_name = sysconfig.get_config_var('DLLLIBRARY') or sysconfig.get_config_var('LDLIBRARY')
-    if not raw_name:
-        raise SystemExit('Could not determine Python DLL name')
+    raw_name = sysconfig.get_config_var('DLLLIBRARY') or sysconfig.get_config_var('LDLIBRARY') or ''
     dll_name = _normalize_dll_name(raw_name)
     include_dir = sysconfig.get_config_var('INCLUDEPY')
     if not include_dir:

From 4de4cc3e33a202fb2c146bfed973de4e89b4596f Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 03:02:22 +0000
Subject: [PATCH 21/25] Remove pkgconfig check

---
 bin/cibw_before_build_windows_arm64.sh | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/bin/cibw_before_build_windows_arm64.sh b/bin/cibw_before_build_windows_arm64.sh
index e07e529c..797f3785 100755
--- a/bin/cibw_before_build_windows_arm64.sh
+++ b/bin/cibw_before_build_windows_arm64.sh
@@ -53,7 +53,12 @@ rm -f "$def_path_msys" "$import_lib_msys"
     cd "$lib_dir_msys"
     gendef "$dll_path_msys"
 )
+echo "Generating $import_lib_msys with $dlltool"
 "$dlltool" -d "$def_path_msys" -D "$DLL_NAME" -l "$import_lib_msys"
+if [ ! -f "$import_lib_msys" ]; then
+    echo "Failed to create $import_lib_msys" >&2
+    exit 1
+fi
 
 cat > "$pc_path_msys" <<EOF
 prefix=$REPO_ROOT
@@ -68,9 +73,5 @@ Libs: -L\${libdir} -l$dll_stem
 Cflags: -I\${includedir}
 EOF
 
-if command -v pkg-config >/dev/null 2>&1; then
-    pkg-config --exists "python-$PKG_VERSION"
-fi
-
 echo "Generated $import_lib_msys"
 echo "Generated $pc_path_msys"

From 88ffa03da1a51cb13ae53ebaf966e0f541e13cfe Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 03:54:17 +0000
Subject: [PATCH 22/25] Try this ...

---
 .github/workflows/buildwheel.yml       |  1 +
 bin/cibw_before_build_windows_arm64.py | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index 6373cb28..265d7762 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -64,6 +64,7 @@ jobs:
         env:
           CIBW_BEFORE_ALL_WINDOWS: msys2 -c bin/cibw_before_all_windows_arm64.sh
           CIBW_BEFORE_BUILD_WINDOWS: python bin/cibw_before_build_windows_arm64.py && msys2 -c bin/cibw_before_build_windows_arm64.sh && pip install wheel delvewheel
+          PYTHONPATH: ${{ github.workspace }}\.local\python-site
 
         # After all the Windows-specific steps above this is what actually
         # builds the wheels for every other OS:
diff --git a/bin/cibw_before_build_windows_arm64.py b/bin/cibw_before_build_windows_arm64.py
index 05c0f250..5cc800bd 100755
--- a/bin/cibw_before_build_windows_arm64.py
+++ b/bin/cibw_before_build_windows_arm64.py
@@ -80,7 +80,18 @@ def main() -> None:
     env_path = repo_root / '.local' / 'cibw_before_build_windows_arm64.env'
     env_text = ''.join(f'{key}={shlex.quote(value)}\n' for key, value in values.items())
     env_path.write_text(env_text, encoding='utf-8')
+
+    python_site = repo_root / '.local' / 'python-site'
+    python_site.mkdir(parents=True, exist_ok=True)
+    sitecustomize = python_site / 'sitecustomize.py'
+    sitecustomize.write_text(
+        'import sysconfig\n'
+        f"sysconfig.get_config_vars()['LIBPC'] = {values['PKGCONFIG_DIR']!r}\n",
+        encoding='utf-8',
+    )
+
     print(f'Generated {env_path}')
+    print(f'Generated {sitecustomize}')
 
 
 if __name__ == '__main__':

From d2b3303e0535b9a0041a2354784b668a3a5f2c4e Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 14:06:12 +0000
Subject: [PATCH 23/25] Add MS_WIN64 define

---
 bin/cibw_before_build_windows_arm64.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/bin/cibw_before_build_windows_arm64.sh b/bin/cibw_before_build_windows_arm64.sh
index 797f3785..a318b24d 100755
--- a/bin/cibw_before_build_windows_arm64.sh
+++ b/bin/cibw_before_build_windows_arm64.sh
@@ -70,7 +70,7 @@ Name: Python
 Description: CPython import library for MinGW wheel builds
 Version: $PKG_VERSION
 Libs: -L\${libdir} -l$dll_stem
-Cflags: -I\${includedir}
+Cflags: -DMS_WIN64 -I\${includedir}
 EOF
 
 echo "Generated $import_lib_msys"

From 0b9b982d8cb9677c3bdfcc963ee5f05fa0c2c2b5 Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 14:55:32 +0000
Subject: [PATCH 24/25] Try to force using msys2 clangarm64 for Windows on ARM

---
 .github/workflows/buildwheel.yml       | 11 +++++++++++
 bin/cibw_before_build_windows_arm64.sh |  2 +-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/buildwheel.yml b/.github/workflows/buildwheel.yml
index 265d7762..3ddfedb4 100644
--- a/.github/workflows/buildwheel.yml
+++ b/.github/workflows/buildwheel.yml
@@ -36,6 +36,17 @@ jobs:
           msystem: clangarm64
         if: ${{ matrix.os == 'windows-11-arm' }}
 
+      - run: |
+          "C:\\msys64\\clangarm64\\bin" >> $env:GITHUB_PATH
+          "C:\\msys64\\usr\\bin" >> $env:GITHUB_PATH
+          "MSYSTEM=CLANGARM64" >> $env:GITHUB_ENV
+          "CC=clang" >> $env:GITHUB_ENV
+          "CXX=clang++" >> $env:GITHUB_ENV
+          "AR=llvm-ar" >> $env:GITHUB_ENV
+          "RANLIB=llvm-ranlib" >> $env:GITHUB_ENV
+          "STRIP=llvm-strip" >> $env:GITHUB_ENV
+        if: ${{ matrix.os == 'windows-11-arm' }}
+
         # Install pkgconfig on Windows from choco rather than from msys and
         # avoid using the Strawberry one.
       - run: choco install -y --stoponfirstfailure --checksum 6004DF17818F5A6DBF19CB335CC92702 pkgconfiglite
diff --git a/bin/cibw_before_build_windows_arm64.sh b/bin/cibw_before_build_windows_arm64.sh
index a318b24d..066a4818 100755
--- a/bin/cibw_before_build_windows_arm64.sh
+++ b/bin/cibw_before_build_windows_arm64.sh
@@ -69,7 +69,7 @@ includedir=$INCLUDE_DIR
 Name: Python
 Description: CPython import library for MinGW wheel builds
 Version: $PKG_VERSION
-Libs: -L\${libdir} -l$dll_stem
+Libs: $LIB_DIR/lib$dll_stem.dll.a
 Cflags: -DMS_WIN64 -I\${includedir}
 EOF
 

From 37b2f295ef49d5721a02cb47a73b398abb9a83ed Mon Sep 17 00:00:00 2001
From: Oscar Benjamin <oscar.j.benjamin@gmail.com>
Date: Sun, 22 Mar 2026 15:27:57 +0000
Subject: [PATCH 25/25] Add --host again

---
 bin/cibw_before_all_windows_arm64.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/bin/cibw_before_all_windows_arm64.sh b/bin/cibw_before_all_windows_arm64.sh
index 01c38ced..af8f037c 100755
--- a/bin/cibw_before_all_windows_arm64.sh
+++ b/bin/cibw_before_all_windows_arm64.sh
@@ -17,6 +17,7 @@ pacman -S --noconfirm \
 bin/build_dependencies_unix.sh \
     --disable-fat\
     --use-gmp-github-mirror\
+    --host aarch64-pc-windows-gnullvm\
     --patch-C23\
     --patch-ldd\
     #