diff --git a/CMakeLists.txt b/CMakeLists.txt
index 391dc4d72..dac5d4a42 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,8 +36,12 @@ if(NOT DEFINED KANGAROO_ARCH)
 	set(KANGAROO_ARCH x86_64)
 endif()
 
-# Where the superbuild installs the third party libraries for this platform.
-set(BUILD_DIR ${CMAKE_SOURCE_DIR}/.builddir/${KANGAROO_OS}/${KANGAROO_ARCH})
+# Where the superbuild installs the third party libraries for this platform.  SINGE_TREE lets a
+# second toolchain for the same platform keep its own tree (the zig Linux build beside the gcc one).
+if(NOT DEFINED SINGE_TREE)
+	set(SINGE_TREE ${KANGAROO_OS})
+endif()
+set(BUILD_DIR ${CMAKE_SOURCE_DIR}/.builddir/${SINGE_TREE}/${KANGAROO_ARCH})
 set(GENERATED_DIR ${CMAKE_BINARY_DIR}/generated)
 file(MAKE_DIRECTORY ${GENERATED_DIR})
 
@@ -476,8 +480,16 @@ target_link_directories(${CMAKE_PROJECT_NAME} PRIVATE
 if(KANGAROO_OS STREQUAL "linux")
 	# ffmpeg's vdpau hardware context is always compiled in on X11 hosts.
 	set(SYSTEM_LIBS -lX11 -lvdpau -ldl -rdynamic)   # -rdynamic gives the crash backtrace function names
+	# Release binaries are stripped; the crash backtrace reads the dynamic symbols -rdynamic exports,
+	# which stripping keeps.
+	if(CMAKE_BUILD_TYPE STREQUAL "Release")
+		list(APPEND SYSTEM_LIBS -s)
+	endif()
 elseif(KANGAROO_OS STREQUAL "pi")
 	set(SYSTEM_LIBS -ldl)
+	if(CMAKE_BUILD_TYPE STREQUAL "Release")
+		list(APPEND SYSTEM_LIBS -s)
+	endif()
 elseif(KANGAROO_OS STREQUAL "macos")
 	set(SYSTEM_LIBS
 		-Wl,-framework,CoreVideo
@@ -495,10 +507,13 @@ elseif(KANGAROO_OS STREQUAL "macos")
 		-Wl,-weak_framework,CoreHaptics
 		-liconv
 		-lc++
-		${OSXCROSS_TARGET_DIR}/darwin/libclang_rt.osx.a
 	)
-	if(NOT DEFINED OSXCROSS_TARGET_DIR)
-		message(FATAL_ERROR "OSXCROSS_TARGET_DIR must be set for macOS builds.")
+	if(NOT SINGE_ZIG_TARGET)
+		# osxcross builds need clang's runtime library named; zig carries its own.
+		if(NOT DEFINED OSXCROSS_TARGET_DIR)
+			message(FATAL_ERROR "OSXCROSS_TARGET_DIR must be set for macOS builds without zig.")
+		endif()
+		list(APPEND SYSTEM_LIBS ${OSXCROSS_TARGET_DIR}/darwin/libclang_rt.osx.a)
 	endif()
 elseif(KANGAROO_OS STREQUAL "windows")
 	# A GUI-subsystem executable, so no console window opens; zig's linker wants the flag spelled out.
diff --git a/CMakePresets.json b/CMakePresets.json
index 0c30f1ecc..b5f29a6a9 100644
--- a/CMakePresets.json
+++ b/CMakePresets.json
@@ -17,38 +17,28 @@
 		},
 		{
 			"name": "linux-x86_64",
-			"displayName": "Linux x86_64",
+			"displayName": "Linux x86_64 (zig, glibc 2.28, release)",
 			"inherits": "base",
 			"binaryDir": "${sourceDir}/.builddir/linux/x86_64/superbuild",
+			"toolchainFile": "${sourceDir}/cmake/zig/x86_64-linux-gnu.cmake",
+			"cacheVariables": {
+				"SINGE_TRIPLE": "x86_64-linux-gnu",
+				"SINGE_CROSS_OS": "linux",
+				"SINGE_SUFFIX": "",
+				"SINGE_TREE": "linux"
+			}
+		},
+		{
+			"name": "linux-x86_64-gcc",
+			"displayName": "Linux x86_64 (host gcc, developer build)",
+			"inherits": "base",
+			"binaryDir": "${sourceDir}/.builddir/linux-gcc/x86_64/superbuild",
 			"toolchainFile": "${sourceDir}/cmake/linux-x86_64.cmake",
 			"cacheVariables": {
 				"SINGE_TRIPLE": "x86_64-linux-gnu",
 				"SINGE_CROSS_OS": "linux",
-				"SINGE_SUFFIX": ""
-			}
-		},
-		{
-			"name": "pi-aarch64",
-			"displayName": "Raspberry Pi 64-bit",
-			"inherits": "base",
-			"binaryDir": "${sourceDir}/.builddir/pi/aarch64/superbuild",
-			"toolchainFile": "${sourceDir}/../toolchains/cmake/aarch64-rpi3-linux-gnu.cmake",
-			"cacheVariables": {
-				"SINGE_TRIPLE": "aarch64-rpi3-linux-gnu",
-				"SINGE_CROSS_OS": "linux",
-				"SINGE_SUFFIX": ""
-			}
-		},
-		{
-			"name": "macos-aarch64",
-			"displayName": "macOS Apple silicon",
-			"inherits": "base",
-			"binaryDir": "${sourceDir}/.builddir/macos/aarch64/superbuild",
-			"toolchainFile": "${sourceDir}/../toolchains/cmake/aarch64-apple-darwin22.4.cmake",
-			"cacheVariables": {
-				"SINGE_TRIPLE": "aarch64-apple-darwin22.4",
-				"SINGE_CROSS_OS": "darwin",
-				"SINGE_SUFFIX": ""
+				"SINGE_SUFFIX": "-gcc",
+				"SINGE_TREE": "linux-gcc"
 			}
 		},
 		{
@@ -62,6 +52,30 @@
 				"SINGE_CROSS_OS": "mingw32",
 				"SINGE_SUFFIX": ".exe"
 			}
+		},
+		{
+			"name": "pi-aarch64",
+			"displayName": "Raspberry Pi 64-bit (zig)",
+			"inherits": "base",
+			"binaryDir": "${sourceDir}/.builddir/pi/aarch64/superbuild",
+			"toolchainFile": "${sourceDir}/cmake/zig/aarch64-linux-gnu.cmake",
+			"cacheVariables": {
+				"SINGE_TRIPLE": "aarch64-linux-gnu",
+				"SINGE_CROSS_OS": "linux",
+				"SINGE_SUFFIX": ""
+			}
+		},
+		{
+			"name": "macos-aarch64",
+			"displayName": "macOS Apple silicon (zig)",
+			"inherits": "base",
+			"binaryDir": "${sourceDir}/.builddir/macos/aarch64/superbuild",
+			"toolchainFile": "${sourceDir}/cmake/zig/aarch64-macos.cmake",
+			"cacheVariables": {
+				"SINGE_TRIPLE": "aarch64-apple-darwin22.4",
+				"SINGE_CROSS_OS": "darwin",
+				"SINGE_SUFFIX": ""
+			}
 		}
 	],
 	"buildPresets": [
@@ -69,6 +83,14 @@
 			"name": "linux-x86_64",
 			"configurePreset": "linux-x86_64"
 		},
+		{
+			"name": "linux-x86_64-gcc",
+			"configurePreset": "linux-x86_64-gcc"
+		},
+		{
+			"name": "windows-x86_64",
+			"configurePreset": "windows-x86_64"
+		},
 		{
 			"name": "pi-aarch64",
 			"configurePreset": "pi-aarch64"
@@ -76,10 +98,6 @@
 		{
 			"name": "macos-aarch64",
 			"configurePreset": "macos-aarch64"
-		},
-		{
-			"name": "windows-x86_64",
-			"configurePreset": "windows-x86_64"
 		}
 	]
 }
diff --git a/INSTALL b/INSTALL
index af3eeea35..7003d25d2 100644
--- a/INSTALL
+++ b/INSTALL
@@ -63,16 +63,41 @@ pkg-config perl nasm imagemagick lua5.4 ffmpeg asciidoctor
 ruby-asciidoctor-pdf autoconf automake libtool libasound-dev libxi-dev
 libvdpau-dev libva-dev libdrm-dev libgl-dev libx11-dev.
 
-Cross builds need nothing else installed:
+The Linux release build and the Windows build use zig as the compiler:
+the build fetches a pinned zig release (version and SHA-256 in
+cmake/zig/zig.cmake) into .builddir/toolchains on first use.  For Linux it
+targets glibc 2.28, so the binary runs on distributions back to Debian 10
+and Ubuntu 18.04 while linking the host's platform libraries (X11, ALSA,
+VA-API, VDPAU, DRM); for Windows zig carries the headers and import
+libraries itself, so nothing else is installed:
 
   ./build-all.sh windows x86_64
 
-fetches a pinned zig release (version and SHA-256 in cmake/zig/zig.cmake)
-into .builddir/toolchains on first use and uses it as the cross compiler;
-zig carries the Windows headers and import libraries itself.  The Pi and
-macOS presets are not yet self-contained; they still expect the toolchains
-repository beside this one (see PLAN.md section 17 for the plan to move
-them to zig too).
+A developer build with the host's own gcc, glibc and symbols is the
+linux-x86_64-gcc preset (binary Singe-v3.00-Linux-x86_64-gcc).
+
+macOS builds with zig too, but needs an Apple SDK for the frameworks,
+which Apple's licence does not allow a build script to fetch.  Provide it
+once as a tarball holding a single MacOSX*.sdk directory:
+
+  .builddir/toolchains/MacOSX.sdk.tar.xz
+
+On a Mac with Xcode installed, osxcross's tools/gen_sdk_package.sh makes
+exactly that tarball from the installed SDK.  The build unpacks it to
+.builddir/toolchains/MacOSX.sdk on first use.  Alternatively point
+SINGE_MACOS_SDK at an unpacked SDK, or set SINGE_MACOS_SDK_URL (and
+SINGE_MACOS_SDK_SHA256) to have the build fetch the tarball from a
+location of your choosing.  Then:
+
+  ./build-all.sh macos aarch64
+
+The Raspberry Pi build (64-bit Raspberry Pi OS, glibc 2.31 or newer)
+also uses zig.  The platform headers and libraries it links against are
+Debian bookworm arm64 packages listed in cmake/zig/piPackages.cmake,
+fetched from snapshot.debian.org and unpacked with dpkg-deb into
+.builddir/toolchains/sysroot-aarch64-linux-gnu on first use:
+
+  ./build-all.sh pi aarch64
 
 Useful forms (anything after the platform goes to cmake --build):
 
@@ -83,5 +108,5 @@ Without the wrapper:
 
   cmake --preset linux-x86_64 && cmake --build --preset linux-x86_64
 
-Presets:  linux-x86_64, windows-x86_64, pi-aarch64, macos-aarch64
-(CMakePresets.json).
+Presets:  linux-x86_64, linux-x86_64-gcc, windows-x86_64, pi-aarch64,
+macos-aarch64 (CMakePresets.json).
diff --git a/build-all.sh b/build-all.sh
index a29120ed9..7a9c6cbea 100755
--- a/build-all.sh
+++ b/build-all.sh
@@ -39,20 +39,8 @@ function buildAll() {
 	local ARCH=$2
 	shift 2
 
-	# Linux builds with the host compiler and Windows with the zig the build fetches itself.  The Pi
-	# and macOS presets still lean on the toolchains repository beside this one until they move to
-	# zig as well (PLAN.md section 17).
-	if [[ "${OS}" == "pi" || "${OS}" == "macos" ]]; then
-		if [[ ! -x ../toolchains/toolchains.sh ]]; then
-			echo "error: ${OS} still needs ../toolchains/toolchains.sh" >&2
-			exit 1
-		fi
-		source <(../toolchains/toolchains.sh use ${ARCH} ${OS})
-		if [[ "${OS}" == "pi" ]]; then
-			sudo chroot ${SYSROOT} apt-get -y install libasound-dev libxi-dev libvdpau-dev libdrm-dev
-		fi
-	fi
-
+	# Every platform builds with the zig the build fetches itself; the Pi preset also fetches its
+	# platform packages and macOS needs the Apple SDK tarball (see INSTALL).
 	cmake --preset ${OS}-${ARCH}
 	cmake --build --preset ${OS}-${ARCH} "$@"
 }
diff --git a/cmake/Superbuild.cmake b/cmake/Superbuild.cmake
index 4889cdd72..4b9325e81 100644
--- a/cmake/Superbuild.cmake
+++ b/cmake/Superbuild.cmake
@@ -81,7 +81,7 @@ set(SB_PKG_CONFIG_LIBDIR "${SB_PREFIX}/lib/pkgconfig")
 if(KANGAROO_OS STREQUAL "linux")
 	set(SB_PKG_CONFIG_LIBDIR "${SB_PKG_CONFIG_LIBDIR}:/usr/lib/${SINGE_TRIPLE}/pkgconfig:/usr/lib/pkgconfig:/usr/share/pkgconfig")
 elseif(KANGAROO_OS STREQUAL "pi")
-	set(SB_PKG_CONFIG_LIBDIR "${SB_PKG_CONFIG_LIBDIR}:${CMAKE_SYSROOT}/usr/lib/${SINGE_TRIPLE}/pkgconfig:${CMAKE_SYSROOT}/usr/lib/pkgconfig:${CMAKE_SYSROOT}/usr/share/pkgconfig")
+	set(SB_PKG_CONFIG_LIBDIR "${SB_PKG_CONFIG_LIBDIR}:${SINGE_SYSROOT}/usr/lib/${SINGE_TRIPLE}/pkgconfig:${SINGE_SYSROOT}/usr/lib/pkgconfig:${SINGE_SYSROOT}/usr/share/pkgconfig")
 elseif(DEFINED ENV{PKG_CONFIG_LIBDIR})
 	set(SB_PKG_CONFIG_LIBDIR "${SB_PKG_CONFIG_LIBDIR}:$ENV{PKG_CONFIG_LIBDIR}")
 endif()
@@ -104,7 +104,7 @@ function(singeStepEnv outVar cflags)
 		list(APPEND env "AR=${CMAKE_AR}")
 	endif()
 	if(KANGAROO_OS STREQUAL "pi")
-		list(APPEND env "PKG_CONFIG_SYSROOT_DIR=${CMAKE_SYSROOT}")
+		list(APPEND env "PKG_CONFIG_SYSROOT_DIR=${SINGE_SYSROOT}")
 	endif()
 	set(${outVar} ${env} PARENT_SCOPE)
 endfunction()
@@ -210,6 +210,8 @@ elseif(KANGAROO_OS STREQUAL "macos")
 	else()
 		set(opensslTarget darwin64-x86_64)
 	endif()
+elseif(SINGE_ZIG_TARGET)
+	set(opensslTarget linux-x86_64)
 else()
 	set(opensslTarget "")
 endif()
@@ -221,13 +223,14 @@ else()
 	set(opensslAsm "")
 endif()
 # OpenSSL's Configure derives the source tree from the build directory's position and only
-# copes with a build directory nested inside its own tree, so this one lives there.
-set(opensslBinary ${SB_THIRDPARTY}/openssl/.builddir)
+# copes with a build directory nested inside its own tree, so this one lives there, one per target
+# so that switching presets never links another architecture's objects.
+set(opensslBinary ${SB_THIRDPARTY}/openssl/.builddir/${KANGAROO_OS}-${KANGAROO_ARCH})
 ExternalProject_Add(openssl
 	SOURCE_DIR        ${SB_THIRDPARTY}/openssl
 	BINARY_DIR        ${opensslBinary}
 	DEPENDS           zlib zstd
-	CONFIGURE_COMMAND ${SB_ENV} perl ../Configure ${opensslTarget} --prefix=${SB_PREFIX} --libdir=lib --with-zlib-include=${SB_PREFIX}/include --with-zlib-lib=${SB_PREFIX}/lib --with-zstd-include=${SB_PREFIX}/include --with-zstd-lib=${SB_PREFIX}/lib ${opensslAsm} no-apps no-docs no-dso no-dynamic-engine no-module no-shared no-tests zlib enable-zstd
+	CONFIGURE_COMMAND ${SB_ENV} perl ../../Configure ${opensslTarget} --prefix=${SB_PREFIX} --libdir=lib --with-zlib-include=${SB_PREFIX}/include --with-zlib-lib=${SB_PREFIX}/lib --with-zstd-include=${SB_PREFIX}/include --with-zstd-lib=${SB_PREFIX}/lib ${opensslAsm} no-apps no-docs no-dso no-dynamic-engine no-module no-shared no-tests zlib enable-zstd
 	BUILD_COMMAND     ${SB_ENV} make build_sw
 	INSTALL_COMMAND   ${SB_ENV} make install_sw
 	LOG_CONFIGURE ON LOG_BUILD ON LOG_INSTALL ON LOG_OUTPUT_ON_FAILURE ON
@@ -241,8 +244,6 @@ if(KANGAROO_OS STREQUAL "linux")
 	set(hwaccel --enable-vaapi --enable-vdpau --enable-libdrm)
 elseif(KANGAROO_OS STREQUAL "pi")
 	set(hwaccel --enable-v4l2-m2m --enable-libdrm)
-	# FFmpeg still includes a header the Pi's libc dropped.
-	file(WRITE ${SB_PREFIX}/include/sys/sysctl.h "/* File no longer used */\n")
 elseif(KANGAROO_OS STREQUAL "macos")
 	set(hwaccel --enable-videotoolbox)
 elseif(KANGAROO_OS STREQUAL "windows")
@@ -250,13 +251,22 @@ elseif(KANGAROO_OS STREQUAL "windows")
 else()
 	set(hwaccel "")
 endif()
-# With a classic cross toolchain every tool is <triple>-<tool>; with zig each is named outright and
-# the host's nm reads the target's objects (binutils understands PE and Mach-O).
+# With a classic cross toolchain every tool is <triple>-<tool>; with zig each is named outright.
 if(SINGE_ZIG_TARGET)
-	set(ffmpegTools --enable-cross-compile --cc=${SB_CC} --cxx=${SB_CXX} --ar=${CMAKE_AR} --ranlib=${SB_RANLIB} --nm=nm --windres=${CMAKE_RC_COMPILER})
+	set(ffmpegTools --enable-cross-compile --cc=${SB_CC} --cxx=${SB_CXX} --ar=${CMAKE_AR} --ranlib=${SB_RANLIB} --windres=${CMAKE_RC_COMPILER})
+	# The host's binutils nm reads x86 ELF and PE objects but not aarch64 or Mach-O ones; FFmpeg only
+	# uses nm to learn the symbol prefix, which is empty everywhere but macOS, so the others go without.
+	if(KANGAROO_ARCH STREQUAL "x86_64")
+		list(APPEND ffmpegTools --nm=nm)
+	endif()
 else()
 	set(ffmpegTools --cross-prefix=${SINGE_TRIPLE}- --cc=${SB_CC} --cxx=${SB_CXX} --ranlib=${SB_RANLIB})
 endif()
+# FFmpeg's configure sees sys/sysctl.h in the Pi sysroot and in zig's glibc header set, then its
+# build cannot include it; an empty stand-in satisfies both (Linux uses sysconf, not sysctl).
+if((KANGAROO_OS STREQUAL "pi") OR ((KANGAROO_OS STREQUAL "linux") AND SINGE_ZIG_TARGET))
+	file(WRITE ${SB_PREFIX}/include/sys/sysctl.h "/* File no longer used */\n")
+endif()
 set(ffmpegBinary ${SB_PREFIX}/build/ffmpeg)
 ExternalProject_Add(ffmpeg
 	SOURCE_DIR        ${SB_THIRDPARTY}/ffmpeg
@@ -274,15 +284,18 @@ singeRebuildTarget(ffmpeg)
 string(SUBSTRING ${KANGAROO_OS} 0 1 osInitial)
 string(SUBSTRING ${KANGAROO_OS} 1 -1 osRest)
 string(TOUPPER ${osInitial} osInitial)
-set(singeBinaryName "Singe-v${PROJECT_VERSION}-${osInitial}${osRest}-${KANGAROO_ARCH}${SINGE_SUFFIX}")
+# The built file carries the platform's executable suffix; the copy in .builddir/ carries the
+# preset's, which is the same thing for Windows and lets an experimental build live beside another.
+set(singeBinaryBase "Singe-v${PROJECT_VERSION}-${osInitial}${osRest}-${KANGAROO_ARCH}")
+set(singeBinaryName "${singeBinaryBase}${SINGE_SUFFIX}")
 set(singeBinary ${SB_PREFIX}/singe)
 ExternalProject_Add(singe
 	SOURCE_DIR        ${CMAKE_SOURCE_DIR}
 	BINARY_DIR        ${singeBinary}
 	DEPENDS           zlib zstd SDL3 SDL3_image SDL3_mixer SDL3_ttf openssl ffmpeg
-	CONFIGURE_COMMAND ${SB_ENV} ${CMAKE_COMMAND} -S ${CMAKE_SOURCE_DIR} -B ${singeBinary} ${SB_CMAKE_ARGS} -DSINGE_SUPERBUILD=OFF -DKANGAROO_OS=${KANGAROO_OS} -DKANGAROO_ARCH=${KANGAROO_ARCH}
+	CONFIGURE_COMMAND ${SB_ENV} ${CMAKE_COMMAND} -S ${CMAKE_SOURCE_DIR} -B ${singeBinary} ${SB_CMAKE_ARGS} -DSINGE_SUPERBUILD=OFF -DKANGAROO_OS=${KANGAROO_OS} -DKANGAROO_ARCH=${KANGAROO_ARCH} -DSINGE_TREE=${SINGE_TREE}
 	BUILD_COMMAND     ${SB_ENV} ${CMAKE_COMMAND} --build ${singeBinary} --parallel ${SB_JOBS}
-	INSTALL_COMMAND   ${CMAKE_COMMAND} -E copy ${singeBinary}/${singeBinaryName} ${CMAKE_SOURCE_DIR}/.builddir/${singeBinaryName}
+	INSTALL_COMMAND   ${CMAKE_COMMAND} -E copy ${singeBinary}/${singeBinaryBase}${CMAKE_EXECUTABLE_SUFFIX} ${CMAKE_SOURCE_DIR}/.builddir/${singeBinaryName}
 	BUILD_ALWAYS      ON
 )
 
diff --git a/cmake/zig/aarch64-linux-gnu.cmake b/cmake/zig/aarch64-linux-gnu.cmake
new file mode 100644
index 000000000..4c9a5f858
--- /dev/null
+++ b/cmake/zig/aarch64-linux-gnu.cmake
@@ -0,0 +1,93 @@
+#
+#  Singe 3
+#  Copyright (C) 2006-2026 Scott Duensing <scott@kangaroopunch.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public Licens
+# as published by the Free Software Foundation; either version 3
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+#
+# Raspberry Pi (64-bit Raspberry Pi OS) with zig as the compiler.  zig supplies glibc pinned to the
+# version below plus the kernel headers; the platform libraries Singe, SDL3 and FFmpeg build against
+# (libdrm, ALSA, X11, GBM/EGL/GLES, udev, ...) come from the Debian packages listed in
+# piPackages.cmake, downloaded and unpacked into a sysroot under .builddir/toolchains on first use.
+# Nothing outside the source tree is touched; dpkg-deb from the host does the unpacking.
+
+include(${CMAKE_CURRENT_LIST_DIR}/zig.cmake)
+include(${CMAKE_CURRENT_LIST_DIR}/piPackages.cmake)
+
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR aarch64)
+
+# Raspberry Pi OS bullseye shipped glibc 2.31; a binary built against it runs there and on everything since.
+set(SINGE_GLIBC_VERSION 2.31)
+
+get_filename_component(piToolchains ${CMAKE_CURRENT_LIST_DIR}/../../.builddir/toolchains ABSOLUTE)
+set(SINGE_SYSROOT ${piToolchains}/sysroot-aarch64-linux-gnu CACHE PATH "Pi platform headers and libraries" FORCE)
+set(piDebs ${piToolchains}/debs-aarch64-linux-gnu)
+set(piStamp ${SINGE_SYSROOT}/.complete)
+
+# The stamp holds the manifest that built the sysroot; a changed manifest rebuilds it.
+string(SHA256 piManifest "${piPackages}")
+set(piHave "")
+if(EXISTS ${piStamp})
+	file(READ ${piStamp} piHave)
+	string(STRIP "${piHave}" piHave)
+endif()
+if(NOT piHave STREQUAL piManifest)
+	find_program(SINGE_DPKG_DEB dpkg-deb)
+	if(NOT SINGE_DPKG_DEB)
+		message(FATAL_ERROR "dpkg-deb is needed to unpack the Pi sysroot packages (apt-get install dpkg).")
+	endif()
+	message(STATUS "Building the Pi sysroot in ${SINGE_SYSROOT}")
+	file(REMOVE_RECURSE ${SINGE_SYSROOT})
+	file(MAKE_DIRECTORY ${SINGE_SYSROOT} ${piDebs})
+	foreach(entry IN LISTS piPackages)
+		string(REGEX MATCH "^([^|]*)\\|(.*)$" unused "${entry}")
+		set(url ${CMAKE_MATCH_1})
+		set(sha ${CMAKE_MATCH_2})
+		get_filename_component(deb ${url} NAME)
+		set(debPath ${piDebs}/${deb})
+		if(NOT EXISTS ${debPath})
+			message(STATUS "Downloading ${deb}")
+			file(DOWNLOAD ${url} ${debPath} EXPECTED_HASH SHA256=${sha} STATUS status)
+			list(GET status 0 code)
+			if(NOT code EQUAL 0)
+				file(REMOVE ${debPath})
+				message(FATAL_ERROR "Download of ${url} failed:  ${status}")
+			endif()
+		endif()
+		execute_process(COMMAND ${SINGE_DPKG_DEB} -x ${debPath} ${SINGE_SYSROOT} RESULT_VARIABLE code)
+		if(NOT code EQUAL 0)
+			message(FATAL_ERROR "Unpacking ${deb} failed.")
+		endif()
+	endforeach()
+	file(WRITE ${piStamp} "${piManifest}\n")
+endif()
+
+# The sysroot's headers come after zig's own; its libraries are linked by name and left unresolved
+# at link time (they are only stubs for what the Pi provides at run time).
+set(piLibs ${SINGE_SYSROOT}/usr/lib/aarch64-linux-gnu)
+singeZigToolchain(aarch64-linux-gnu.${SINGE_GLIBC_VERSION} "-idirafter ${SINGE_SYSROOT}/usr/include/aarch64-linux-gnu -idirafter ${SINGE_SYSROOT}/usr/include -L${piLibs} -L${SINGE_SYSROOT}/lib/aarch64-linux-gnu -Wl,--allow-shlib-undefined")
+
+# find_package and pkg-config look only in the sysroot; programs come from the host.
+set(CMAKE_FIND_ROOT_PATH ${SINGE_SYSROOT})
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
+set(CMAKE_LIBRARY_ARCHITECTURE aarch64-linux-gnu CACHE STRING "" FORCE)
+set(CMAKE_C_LIBRARY_ARCHITECTURE aarch64-linux-gnu CACHE STRING "" FORCE)
+set(CMAKE_LIBRARY_PATH ${piLibs} CACHE PATH "" FORCE)
+set(KANGAROO_OS pi)
+set(KANGAROO_ARCH aarch64)
diff --git a/cmake/zig/aarch64-macos.cmake b/cmake/zig/aarch64-macos.cmake
new file mode 100644
index 000000000..57eeab5f1
--- /dev/null
+++ b/cmake/zig/aarch64-macos.cmake
@@ -0,0 +1,81 @@
+#
+#  Singe 3
+#  Copyright (C) 2006-2026 Scott Duensing <scott@kangaroopunch.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public Licens
+# as published by the Free Software Foundation; either version 3
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+#
+# macOS on Apple silicon with zig as the compiler.  zig carries the macOS libc headers and the
+# libSystem stub itself; everything else (Cocoa, CoreAudio, VideoToolbox, Metal and the rest of
+# the frameworks, libc++, libiconv) comes from an Apple SDK, which Apple does not let a build
+# script fetch.  The SDK is expected, in this order:
+#   1.  an unpacked SDK at SINGE_MACOS_SDK (default .builddir/toolchains/MacOSX.sdk);
+#   2.  a tarball at .builddir/toolchains/MacOSX.sdk.tar.xz, unpacked on first use;
+#   3.  SINGE_MACOS_SDK_URL (with SINGE_MACOS_SDK_SHA256), downloaded and unpacked on first use.
+# See INSTALL for how to make the tarball from Xcode.
+
+include(${CMAKE_CURRENT_LIST_DIR}/zig.cmake)
+
+set(CMAKE_SYSTEM_NAME Darwin)
+set(CMAKE_SYSTEM_PROCESSOR arm64)
+
+get_filename_component(sdkToolchains ${CMAKE_CURRENT_LIST_DIR}/../../.builddir/toolchains ABSOLUTE)
+set(SINGE_MACOS_SDK ${sdkToolchains}/MacOSX.sdk CACHE PATH "Unpacked Apple SDK for the macOS build")
+set(SINGE_MACOS_SDK_URL "" CACHE STRING "Where to fetch the Apple SDK tarball from, if anywhere")
+set(SINGE_MACOS_SDK_SHA256 "" CACHE STRING "SHA-256 of that tarball")
+set(sdkTarball ${sdkToolchains}/MacOSX.sdk.tar.xz)
+if(NOT EXISTS ${SINGE_MACOS_SDK}/System/Library/Frameworks/Cocoa.framework)
+	if((NOT EXISTS ${sdkTarball}) AND SINGE_MACOS_SDK_URL)
+		message(STATUS "Downloading the Apple SDK from ${SINGE_MACOS_SDK_URL}")
+		file(MAKE_DIRECTORY ${sdkToolchains})
+		if(SINGE_MACOS_SDK_SHA256)
+			file(DOWNLOAD ${SINGE_MACOS_SDK_URL} ${sdkTarball} EXPECTED_HASH SHA256=${SINGE_MACOS_SDK_SHA256} STATUS status)
+		else()
+			file(DOWNLOAD ${SINGE_MACOS_SDK_URL} ${sdkTarball} STATUS status)
+		endif()
+		list(GET status 0 code)
+		if(NOT code EQUAL 0)
+			message(FATAL_ERROR "Apple SDK download failed:  ${status}")
+		endif()
+	endif()
+	if(EXISTS ${sdkTarball})
+		message(STATUS "Unpacking ${sdkTarball}")
+		set(sdkUnpack ${sdkToolchains}/MacOSX.sdk.unpack)
+		file(REMOVE_RECURSE ${sdkUnpack})
+		file(ARCHIVE_EXTRACT INPUT ${sdkTarball} DESTINATION ${sdkUnpack})
+		file(GLOB sdkFound LIST_DIRECTORIES true ${sdkUnpack}/*.sdk ${sdkUnpack}/*/*.sdk)
+		list(LENGTH sdkFound sdkCount)
+		if(NOT sdkCount EQUAL 1)
+			message(FATAL_ERROR "${sdkTarball} should hold exactly one MacOSX*.sdk directory; found ${sdkCount}.")
+		endif()
+		file(RENAME ${sdkFound} ${SINGE_MACOS_SDK})
+		file(REMOVE_RECURSE ${sdkUnpack})
+	endif()
+endif()
+if(NOT EXISTS ${SINGE_MACOS_SDK}/System/Library/Frameworks/Cocoa.framework)
+	message(FATAL_ERROR "No Apple SDK at ${SINGE_MACOS_SDK}.  Put an SDK tarball at ${sdkTarball} (see INSTALL), or set SINGE_MACOS_SDK to an unpacked SDK, or SINGE_MACOS_SDK_URL to fetch one.")
+endif()
+
+# The SDK's headers come after zig's own libc headers; frameworks and stub libraries from the SDK.
+singeZigToolchain(aarch64-macos "--sysroot=${SINGE_MACOS_SDK} -idirafter ${SINGE_MACOS_SDK}/usr/include -F${SINGE_MACOS_SDK}/System/Library/Frameworks -L${SINGE_MACOS_SDK}/usr/lib")
+set(CMAKE_OSX_SYSROOT ${SINGE_MACOS_SDK} CACHE PATH "Apple SDK" FORCE)
+set(CMAKE_OSX_ARCHITECTURES "" CACHE STRING "Left empty; the zig target names the architecture" FORCE)
+set(CMAKE_FIND_ROOT_PATH ${SINGE_MACOS_SDK})
+set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
+set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
+set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
+set(KANGAROO_OS macos)
+set(KANGAROO_ARCH aarch64)
diff --git a/cmake/zig/piPackages.cmake b/cmake/zig/piPackages.cmake
new file mode 100644
index 000000000..44be12974
--- /dev/null
+++ b/cmake/zig/piPackages.cmake
@@ -0,0 +1,78 @@
+# Debian bookworm arm64 packages that give the Pi build its platform headers and stub libraries
+# (libdrm, ALSA, X11, GBM/EGL/GLES, udev, dbus, Wayland, PulseAudio).  zig supplies libc and the
+# kernel headers itself, so no libc6 package is here.  Every line is a permanent snapshot.debian.org
+# URL and the SHA-256 Debian publishes for it; regenerate against a newer snapshot when needed.
+# Format:  one "url|sha256" pair per list element.
+
+set(piPackagesSnapshot "https://snapshot.debian.org/archive/debian/20250901T000000Z")
+set(piPackages
+	"${piPackagesSnapshot}/pool/main/libd/libdrm/libdrm-dev_2.4.114-1+b1_arm64.deb|26d7d0dcbbda8ed023b57989e0fca7f0ff8372daaf654daf8b3a362557be5e21"
+	"${piPackagesSnapshot}/pool/main/libd/libdrm/libdrm2_2.4.114-1+b1_arm64.deb|f5f15a46d02cf5d9fa52d4f1c54b8cf80c398711ad771a9938b12399b8d8090c"
+	"${piPackagesSnapshot}/pool/main/libd/libdrm/libdrm-amdgpu1_2.4.114-1+b1_arm64.deb|24692e933b98b2b8b80d87c45728efa2bc7176120ce9efcb8793407e508b5a32"
+	"${piPackagesSnapshot}/pool/main/libd/libdrm/libdrm-nouveau2_2.4.114-1+b1_arm64.deb|2acf0db609e8569dd89eea5f3e6f27968de50474d31213665901ad1c6d1133de"
+	"${piPackagesSnapshot}/pool/main/libd/libdrm/libdrm-radeon1_2.4.114-1+b1_arm64.deb|e53c2b4be53b4a8e6413887525c9172bdc95ed3a140a52ce23d6e1a68789aaa0"
+	"${piPackagesSnapshot}/pool/main/a/alsa-lib/libasound2-dev_1.2.8-1+b1_arm64.deb|263668e5ce831d3a8426bd342beba7e94925e893a4a5a285252b8f3ed6b3f5ee"
+	"${piPackagesSnapshot}/pool/main/a/alsa-lib/libasound2_1.2.8-1+b1_arm64.deb|9fa889400fcee4b92c8f4a2fafbb7f2cd33444d9ec1665a71002ab67c06114bb"
+	"${piPackagesSnapshot}/pool/main/a/alsa-lib/libasound2-data_1.2.8-1_all.deb|fe0780d2d3674b2977e0acb0d48b448ad72ba1642564b7dc537f55e839984c2d"
+	"${piPackagesSnapshot}/pool/main/libx/libx11/libx11-dev_1.8.4-2+deb12u2_arm64.deb|34bfc833561de983cfb4475523fedc13abb4faee14a876300de659591779add8"
+	"${piPackagesSnapshot}/pool/main/libx/libx11/libx11-6_1.8.4-2+deb12u2_arm64.deb|d1d533e983582282a9ea82c87ac5ce715a9b67bd6d1acbd2439a11c63c36549b"
+	"${piPackagesSnapshot}/pool/main/libx/libxcb/libxcb1-dev_1.15-1_arm64.deb|87b5c3f1bb130727df68295ecfaadc305ee10c150afeb1a183e95b9150e18db5"
+	"${piPackagesSnapshot}/pool/main/libx/libxcb/libxcb1_1.15-1_arm64.deb|041d9a68415c3ccf3ce8f4f8b88e4bbfb5dc1f0d97013c6ef8423e620ea50f84"
+	"${piPackagesSnapshot}/pool/main/libx/libxau/libxau-dev_1.0.9-1_arm64.deb|21db3761a8f388fc83707c00fac645d4332737a859dd727571e1e6ede003b048"
+	"${piPackagesSnapshot}/pool/main/libx/libxau/libxau6_1.0.9-1_arm64.deb|36c2bf400641a80521093771dc2562c903df4065f9eb03add50d90564337ea6c"
+	"${piPackagesSnapshot}/pool/main/libx/libxdmcp/libxdmcp-dev_1.1.2-3_arm64.deb|6fd0bc51f3a4e6b7f944f24f15524a4c4ba68a4b0aa136c18bdb96a2d36988f2"
+	"${piPackagesSnapshot}/pool/main/libx/libxdmcp/libxdmcp6_1.1.2-3_arm64.deb|e92569ac33247261aa09adfadc34ced3994ac301cf8b58de415a2d5dbf15ccfc"
+	"${piPackagesSnapshot}/pool/main/x/xorgproto/x11proto-dev_2022.1-1_all.deb|3cab66a6591774188a568f9b54c4e7956f18da76e0e0fc4a779db5f6bcc3f148"
+	"${piPackagesSnapshot}/pool/main/x/xorg-sgml-doctools/xorg-sgml-doctools_1.11-1.1_all.deb|168345058319094e475a87ace66f5fb6ae802109650ea8434d672117982b5d0a"
+	"${piPackagesSnapshot}/pool/main/libx/libxext/libxext-dev_1.3.4-1+b1_arm64.deb|07f5e3efeba9564071885b2d0d2ba277692fa309a9f05ef862688af0022b1fcf"
+	"${piPackagesSnapshot}/pool/main/libx/libxext/libxext6_1.3.4-1+b1_arm64.deb|5e9c0ad606eb4674c645fe8e0e64330c47d2729f7a59ed569848610efd5d5b62"
+	"${piPackagesSnapshot}/pool/main/libx/libxi/libxi-dev_1.8-1+b1_arm64.deb|4a5e7bc3b4e55c23281b2e500b572a61ae8869b1bc03fe14b4ae5a4c9e3c295c"
+	"${piPackagesSnapshot}/pool/main/libx/libxi/libxi6_1.8-1+b1_arm64.deb|b26383c9929d8bfba051eee22301e064d17039ed022bbf31990feb0d7a03b36c"
+	"${piPackagesSnapshot}/pool/main/libx/libxfixes/libxfixes-dev_6.0.0-2_arm64.deb|25266e1bd10c7624210abf3aa3eb85e3886b6c8c08b2ecc396b8a04f24c10082"
+	"${piPackagesSnapshot}/pool/main/libx/libxfixes/libxfixes3_6.0.0-2_arm64.deb|d47bda8fed01b19b41d503e2df05d9166c58e30e2376f2f8784ceb7a834befe6"
+	"${piPackagesSnapshot}/pool/main/libx/libxrandr/libxrandr-dev_1.5.2-2+b1_arm64.deb|f951a3813c525bc950e21e801837dfe447bdbef4d2610eddbd833d7d41f92c7c"
+	"${piPackagesSnapshot}/pool/main/libx/libxrandr/libxrandr2_1.5.2-2+b1_arm64.deb|f0bc7f79fee182caae176652fdb1bf349d13b9591b10ad4dc1c896521da8e49f"
+	"${piPackagesSnapshot}/pool/main/libx/libxrender/libxrender-dev_0.9.10-1.1_arm64.deb|26a3ef50910cae3422c20af90a4a4deb85e7da3680c9192e50efc01b7e1b2f8f"
+	"${piPackagesSnapshot}/pool/main/libx/libxrender/libxrender1_0.9.10-1.1_arm64.deb|f260193deb4eaf0b410a1c61e1f84804366ee3372b8bad9f38005f7dbcd89aae"
+	"${piPackagesSnapshot}/pool/main/libx/libxcursor/libxcursor-dev_1.2.1-1_arm64.deb|5d0a0e62fcb202d9afc08c95d6b44e28211e63a6f0763e05741561ac2580aaa1"
+	"${piPackagesSnapshot}/pool/main/libx/libxcursor/libxcursor1_1.2.1-1_arm64.deb|a93dd172bdd940de4ac6fd2b7a3f0213604c975f9f2f51eb3013f50886aaa87c"
+	"${piPackagesSnapshot}/pool/main/libx/libxtst/libxtst-dev_1.2.3-1.1_arm64.deb|4e205710dd04f9e9ee360da0161c155be01086e36462fead392b707b3857b4f2"
+	"${piPackagesSnapshot}/pool/main/libx/libxtst/libxtst6_1.2.3-1.1_arm64.deb|ef2a1b9ac3f2620d96e17744e41c4eefb7f491eee3bcc5bc1e592180b2d94128"
+	"${piPackagesSnapshot}/pool/main/libx/libxss/libxss-dev_1.2.3-1_arm64.deb|970b39c57df5c1307f905c6dd89967d548e9e2711a2099241de7b8e8831e40ca"
+	"${piPackagesSnapshot}/pool/main/libx/libxss/libxss1_1.2.3-1_arm64.deb|e0ff80e309eacda5face68b9a3bd56718fed2750af429324c35d7c9491c335f4"
+	"${piPackagesSnapshot}/pool/main/libx/libxinerama/libxinerama-dev_1.1.4-3_arm64.deb|64c758aef152615d99bceead07c86b03f3737dca190230b5dde1d79403288341"
+	"${piPackagesSnapshot}/pool/main/libx/libxinerama/libxinerama1_1.1.4-3_arm64.deb|1dc5f458f6b3245b1b128897f905717d3cf7777a5697577b246042e25311d0df"
+	"${piPackagesSnapshot}/pool/main/libx/libxkbcommon/libxkbcommon-dev_1.5.0-1_arm64.deb|7d39b34b202fe58e18992b439c79c149ebb1b821b58dfb863ff4898e06420699"
+	"${piPackagesSnapshot}/pool/main/libx/libxkbcommon/libxkbcommon0_1.5.0-1_arm64.deb|ec518d8a19796a399ab95e7bc4dfbb6bd2ed8e151f77b222df26208db412d852"
+	"${piPackagesSnapshot}/pool/main/m/mesa/libgbm-dev_22.3.6-1+deb12u1_arm64.deb|ba3f413f6f428b45e21d93fc5eb213bbc31ca1c15a7b265da3700100fd2475c8"
+	"${piPackagesSnapshot}/pool/main/m/mesa/libgbm1_22.3.6-1+deb12u1_arm64.deb|c76790e11aac46e328b6a13b34cccd3ef01fad79cfe80d2c4aa2384ac9ddb1f8"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libegl-dev_1.6.0-1_arm64.deb|8a3004f892785a5fa4c9f969c116f567a36d1c8e9b3d5fd0403055151e36c7d3"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libegl1_1.6.0-1_arm64.deb|707097a275155c600e2e9251c4ee7cdfdb2d8f50a678a850a2526a7bc9664166"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libgles-dev_1.6.0-1_arm64.deb|941e9963d64479544691f7183fe0eeae32b53b633df71c4c51263517ab2ea8f3"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libgles2_1.6.0-1_arm64.deb|efeb2717380f8411d66b3f669bb99bbd83ff09db3d4a1661533aa31af659608c"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libgl-dev_1.6.0-1_arm64.deb|56add9e710c072cf56504beed50a639f9f7c64f4e31e66958fa65a566084888c"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libgl1_1.6.0-1_arm64.deb|f4043ab47f52325973d2b608514b3469b055b65c744861c7f378755a32e799d6"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libglvnd-dev_1.6.0-1_arm64.deb|86cba4e243d10ae07cc6e769f23ecd097b2f87b722dc5ac48a48a3794cd29513"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libglvnd0_1.6.0-1_arm64.deb|d5063205fab5322ee686f33f87c6315b3fcd1335ea4e7bc8202b48ed4f9c9e83"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libglx-dev_1.6.0-1_arm64.deb|f3d6fca16c259743208df6f845aee3189eb54fed00e159811135089c16d0ad9c"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libglx0_1.6.0-1_arm64.deb|523f9b71f75e48ae605d8ef298a4b03ade26ade9a808a85329a3bd82a54b9b0d"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libopengl0_1.6.0-1_arm64.deb|4b3c6b3bc25530290cf231acac4c85b8806dda53ab6376ab22b3ec511b4fb7a0"
+	"${piPackagesSnapshot}/pool/main/libg/libglvnd/libopengl-dev_1.6.0-1_arm64.deb|b4ddc2d38103e9f0c3637d46334ccbf40c30e851c85f5348abc0aa37e3926822"
+	"${piPackagesSnapshot}/pool/main/s/systemd/libudev-dev_252.36-1~deb12u1_arm64.deb|62760a9e8fb87c2827333163efadc36c5ae66be59af18e7286d19813b8a72e03"
+	"${piPackagesSnapshot}/pool/main/s/systemd/libudev1_252.36-1~deb12u1_arm64.deb|5abfa6d6960f1b6a19c3d35373958d47a3a2f1221a5fe4652143fea0e0adc2ab"
+	"${piPackagesSnapshot}/pool/main/d/dbus/libdbus-1-dev_1.14.10-1~deb12u1_arm64.deb|817caa440feee88d53dd74432ce633af8d351552cd71014bcc8c98380c9ed88c"
+	"${piPackagesSnapshot}/pool/main/d/dbus/libdbus-1-3_1.14.10-1~deb12u1_arm64.deb|2a423794f44ee756f70fda67c6e47b15afe3dd22cd69e51f5d14d2ec9538f806"
+	"${piPackagesSnapshot}/pool/main/w/wayland/libwayland-dev_1.21.0-1_arm64.deb|932405c58195d299495230792e374ad304adadf3d3ffdc07eda3466b756adc33"
+	"${piPackagesSnapshot}/pool/main/w/wayland/libwayland-client0_1.21.0-1_arm64.deb|ae390cc04c2eb1de90b9a6373505b22c730ada5e72daa50c507b7f99c12faf06"
+	"${piPackagesSnapshot}/pool/main/w/wayland/libwayland-egl1_1.21.0-1_arm64.deb|c08124a4d9af24f058b45c88867a84697882e755ea94965795d152fe26fe57c9"
+	"${piPackagesSnapshot}/pool/main/w/wayland/libwayland-cursor0_1.21.0-1_arm64.deb|8c8d1a3942bc3fc9dd3ea7c679c1a314e59cdaaa700883d54d1bb3ec89db256b"
+	"${piPackagesSnapshot}/pool/main/w/wayland/libwayland-server0_1.21.0-1_arm64.deb|4d99e7e0503fdaa999e67d47d8612c0465e775eafa47819573da50bdb09064f2"
+	"${piPackagesSnapshot}/pool/main/w/wayland/libwayland-bin_1.21.0-1_arm64.deb|02e9361617b43b130ff032873a910258884160c169e89a1ca45d34d1150a2615"
+	"${piPackagesSnapshot}/pool/main/libd/libdecor-0/libdecor-0-dev_0.1.1-2_arm64.deb|e52fbcbbf6e755be2c642fcecc6154d9d071978d0797e7cf9ccf93d131bf4fc6"
+	"${piPackagesSnapshot}/pool/main/libd/libdecor-0/libdecor-0-0_0.1.1-2_arm64.deb|e88d3c2dd3336a97b8cf10ef270a264388fce81cedf8032b18f2a36b021bc6a3"
+	"${piPackagesSnapshot}/pool/main/p/pulseaudio/libpulse-dev_16.1+dfsg1-2+b1_arm64.deb|dac8f94dc214a77654cc62d0f1611cd4dee9cdefdc816e3056dd9fae5aa5d4a8"
+	"${piPackagesSnapshot}/pool/main/p/pulseaudio/libpulse0_16.1+dfsg1-2+b1_arm64.deb|26f17e3457c5fce0104a6b2f0efb75a3256b24b32ca7cfda6266373758a930cb"
+	"${piPackagesSnapshot}/pool/main/w/wayland/libwayland-egl-backend-dev_1.21.0-1_arm64.deb|0974da94059371e67e93d61398853c9967d0cc34cd7745b6d47d3aa47b88815d"
+	"${piPackagesSnapshot}/pool/main/libf/libffi/libffi-dev_3.4.4-1_arm64.deb|8ff6335f76752ef8659762435d0d88129ef0090a587520853238809bd10ef392"
+	"${piPackagesSnapshot}/pool/main/libf/libffi/libffi8_3.4.4-1_arm64.deb|80b5c36177dc0e29d531c7eddbed3cc7355cb490e49f8cfa5959572d161f27b3"
+)
diff --git a/cmake/zig/x86_64-linux-gnu.cmake b/cmake/zig/x86_64-linux-gnu.cmake
new file mode 100644
index 000000000..3cebfa7c4
--- /dev/null
+++ b/cmake/zig/x86_64-linux-gnu.cmake
@@ -0,0 +1,59 @@
+#
+#  Singe 3
+#  Copyright (C) 2006-2026 Scott Duensing <scott@kangaroopunch.com>
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public Licens
+# as published by the Free Software Foundation; either version 3
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+# 02110-1301, USA.
+#
+
+# Linux x86_64 with zig as the compiler, targeting glibc 2.28 (Debian 10, Ubuntu 18.04) so one
+# release binary runs on more distributions than the build host's own glibc allows.  zig supplies
+# libc and its headers; the platform libraries (ALSA, X11, DRM, VA-API, VDPAU, GL) and their
+# headers come from the host's development packages, searched after zig's own so the host's
+# newer glibc headers never shadow the pinned ones.
+
+include(${CMAKE_CURRENT_LIST_DIR}/zig.cmake)
+
+set(SINGE_GLIBC_VERSION 2.28)
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR x86_64)
+
+# The linker may see the host's platform libraries but never its libc, libm, libpthread or gcc
+# runtime, or symbols get bound to the host's newer glibc versions.  A directory of links to
+# everything else under the host's library directory keeps the two apart.
+set(hostLibs ${CMAKE_BINARY_DIR}/hostlibs)
+file(MAKE_DIRECTORY ${hostLibs})
+file(GLOB hostSharedLibs /usr/lib/x86_64-linux-gnu/lib*.so)
+foreach(lib ${hostSharedLibs})
+	get_filename_component(name ${lib} NAME)
+	if(NOT name MATCHES "^lib(c|m|dl|pthread|rt|resolv|util|anl|nsl|crypt|gcc_s|stdc\\+\\+|BrokenLocale|mvec|memusage|pcprofile|SegFault|thread_db|c_malloc_debug|asan|ubsan|tsan|lsan|atomic|gomp|itm|quadmath)\\.so$")
+		if(NOT EXISTS ${hostLibs}/${name})
+			file(CREATE_LINK ${lib} ${hostLibs}/${name} SYMBOLIC)
+		endif()
+	endif()
+endforeach()
+
+# --allow-shlib-undefined:  the host's platform libraries reference its newer glibc; at link time only
+# their symbols matter, and the machine that runs the binary brings its own copies.
+singeZigToolchain(x86_64-linux-gnu.${SINGE_GLIBC_VERSION} "-idirafter /usr/include/x86_64-linux-gnu -idirafter /usr/include -L${hostLibs} -Wl,--allow-shlib-undefined")
+# No find-root restrictions:  the host's development packages are the platform packages here, so
+# SDL3 must find X11, Wayland, ALSA and the rest where they are.  CMake learns the Debian multiarch
+# library directory from gcc, not from a clang-style compiler, and its compiler detection overwrites
+# a plain variable, so the settings are forced into the cache or FindX11 never sees libX11.
+set(CMAKE_LIBRARY_ARCHITECTURE x86_64-linux-gnu CACHE STRING "Debian multiarch library directory name" FORCE)
+set(CMAKE_C_LIBRARY_ARCHITECTURE x86_64-linux-gnu CACHE STRING "Debian multiarch library directory name" FORCE)
+set(CMAKE_LIBRARY_PATH /usr/lib/x86_64-linux-gnu CACHE PATH "Where the host platform libraries live" FORCE)
+set(KANGAROO_OS linux)
+set(KANGAROO_ARCH x86_64)
diff --git a/cmake/zig/x86_64-windows-gnu.cmake b/cmake/zig/x86_64-windows-gnu.cmake
index 85ebe869e..e394241b8 100644
--- a/cmake/zig/x86_64-windows-gnu.cmake
+++ b/cmake/zig/x86_64-windows-gnu.cmake
@@ -25,7 +25,7 @@ include(${CMAKE_CURRENT_LIST_DIR}/zig.cmake)
 
 set(CMAKE_SYSTEM_NAME Windows)
 set(CMAKE_SYSTEM_PROCESSOR x86_64)
-singeZigToolchain(x86_64-windows-gnu)
+singeZigToolchain(x86_64-windows-gnu "")
 set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
diff --git a/cmake/zig/zig.cmake b/cmake/zig/zig.cmake
index acb879356..10d9202d9 100644
--- a/cmake/zig/zig.cmake
+++ b/cmake/zig/zig.cmake
@@ -45,8 +45,9 @@ if(NOT EXISTS ${ZIG_EXECUTABLE})
 	endif()
 endif()
 
-# Writes the wrapper scripts for a target into the build tree and points CMake at them.
-function(singeZigToolchain target)
+# Writes the wrapper scripts for a target into the build tree and points CMake at them.  extra is
+# appended to every compiler invocation (a target's include and library directories).
+function(singeZigToolchain target extra)
 	set(dir ${CMAKE_BINARY_DIR}/zig-${target})
 	file(MAKE_DIRECTORY ${dir})
 	# The compiler wrappers drop one flag:  FFmpeg's configure adds binutils' --pic-executable ASLR
@@ -54,10 +55,12 @@ function(singeZigToolchain target)
 	set(filter "for a in \"$@\"; do [[ $a == -Wl,--pic-executable* ]] || args+=(\"$a\"); done")
 	# -fno-sanitize=undefined:  zig cc instruments for UBSan by default and expects its runtime at
 	# link time; a release build wants neither.
-	foreach(tool "cc;-target ${target} -fno-sanitize=undefined" "c++;-target ${target} -fno-sanitize=undefined" "ar;" "ranlib;" "rc;")
+	# extra goes after the caller's arguments so the caller's -L directories are searched first.
+	foreach(tool "cc;-target ${target} -fno-sanitize=undefined;${extra}" "c++;-target ${target} -fno-sanitize=undefined;${extra}" "ar;;" "ranlib;;" "rc;;")
 		list(GET tool 0 name)
 		list(GET tool 1 args)
-		file(WRITE ${dir}/zig-${name} "#!/bin/bash\nargs=()\n${filter}\nexec \"${ZIG_EXECUTABLE}\" ${name} ${args} \"$\{args[@]}\"\n")
+		list(GET tool 2 after)
+		file(WRITE ${dir}/zig-${name} "#!/bin/bash\nargs=()\n${filter}\nexec \"${ZIG_EXECUTABLE}\" ${name} ${args} \"$\{args[@]}\" ${after}\n")
 		file(CHMOD ${dir}/zig-${name} PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
 	endforeach()
 	set(CMAKE_C_COMPILER   ${dir}/zig-cc     CACHE FILEPATH "C compiler" FORCE)