diff --git a/patches/pkgbuild/meson.sh b/patches/pkgbuild/meson.sh
new file mode 100755
index 0000000..d97294d
--- /dev/null
+++ b/patches/pkgbuild/meson.sh
@@ -0,0 +1,91 @@
+#!/usr/bin/env bash
+# meson: `python -m installer` puts it under /usr/local.
+#
+#   error: failed to commit transaction (conflicting files)
+#   /usr/local/share/man exists in both 'filesystem' and 'meson'
+#
+# Debian and Ubuntu patch sysconfig to prefer the "posix_local" scheme, so the
+# host's python installs a wheel into /usr/local/lib/pythonX.Y/dist-packages
+# with its scripts in /usr/local/bin. An Arch package may not ship /usr/local
+# at all -- the filesystem package owns that tree, and ships
+# usr/local/share/man as a SYMLINK, which is what the conflict is about: our
+# meson shipped a directory where filesystem ships a link.
+#
+# THIRD INSTANCE of this scheme. python-brotli and python-libseccomp were
+# simply dropped, because their wheels could not work on the target anyway.
+# meson cannot be dropped -- stage 2 needs it to rebuild ten packages -- so it
+# gets relocated instead.
+#
+# STAGE-1 ONLY, and listed in build-stage2.sh's STAGE2_SKIP_HOOKS. Inside the
+# chroot the python doing the installing is OUR python, built from Arch's
+# PKGBUILD, whose sysconfig answers /usr/lib/pythonX.Y/site-packages without
+# being asked. The condition disappears, like git's missing zlib-ng headers and
+# libgcrypt's too-old libgpg-error.
+#
+# AND THE VERSION IS THE TARGET'S, NOT THE HOST'S. This is the part that took
+# a failed stage-2 build to see. meson is pure Python, so its ABI does not
+# matter -- but the directory NAME carries a version, and the two pythons
+# disagree:
+#
+#   host python      3.13  ->  /usr/lib/python3.13/site-packages
+#   our python pkg   3.14  ->  /usr/lib/python3.14/site-packages
+#
+# Installed under the host's version, /usr/bin/meson runs in the chroot and
+# then says
+#
+#   ModuleNotFoundError: No module named 'mesonbuild'
+#
+# because the chroot's python -- ours -- never looks in 3.13. So the hook reads
+# the version out of the python PACKAGE in repo/s390x, which is the python that
+# will actually import this. Deriving it from the interpreter running the build
+# is the intuitive thing and the wrong one.
+set -euo pipefail
+python3 - <<'ZZPY'
+import io
+s = io.open("PKGBUILD", encoding="utf-8").read()
+old = '  python -m installer --destdir="$pkgdir" dist/*.whl\n'
+assert s.count(old) == 1, "meson: installer invocation not in the expected form"
+new = old + """  # Debian's posix_local scheme installs to /usr/local; Arch reserves that
+  # tree for the administrator and its filesystem package owns every path in
+  # it. Move what the wheel put there, then take the tree away.
+  local _repo="${REPO:-$HOME/work/arch-s390x/repo/s390x}"
+  # Two layouts to catch. build_package exports
+  # DEB_PYTHON_INSTALL_LAYOUT=deb_system, which keeps the wheel out of
+  # /usr/local -- but leaves it in dist-packages, which Arch's python does not
+  # read. The /usr/local branch stays for anyone running makepkg by hand
+  # without that variable.
+  # The TARGET python's version, read from our own package -- see the note at
+  # the top of this hook. Falls back to the host's only if the package is not
+  # built yet, which would be a stage-1 ordering error worth noticing.
+  local _pyver
+  _pyver=$(bsdtar -xOf "$_repo"/python-[0-9]*.pkg.tar.* .PKGINFO 2>/dev/null \
+           | sed -n 's/^pkgver = \\([0-9]*\\.[0-9]*\\).*/\\1/p' | head -1)
+  if [ -z "$_pyver" ]; then
+    _pyver=$(python -c 'import sys; print("%d.%d" % sys.version_info[:2])')
+    echo "  warning: no python package in $_repo, using host python $_pyver" >&2
+  fi
+  local _site="$pkgdir/usr/lib/python$_pyver/site-packages"
+  if [ -d "$pkgdir/usr/local" ]; then
+    install -dm 755 "$pkgdir/usr/lib/python$_pyver" "$pkgdir/usr/bin"
+    [ -d "$pkgdir/usr/local/lib/python$_pyver/dist-packages" ] && \\
+      mv "$pkgdir/usr/local/lib/python$_pyver/dist-packages" "$_site"
+    [ -d "$pkgdir/usr/local/bin" ] && mv "$pkgdir/usr/local/bin/"* "$pkgdir/usr/bin/"
+    rm -rf "$pkgdir/usr/local"
+  fi
+  if [ -d "$pkgdir/usr/lib/python3/dist-packages" ]; then
+    install -dm 755 "$pkgdir/usr/lib/python$_pyver"
+    if [ -d "$_site" ]; then
+      cp -a "$pkgdir/usr/lib/python3/dist-packages/." "$_site/"
+      rm -rf "$pkgdir/usr/lib/python3/dist-packages"
+    else
+      mv "$pkgdir/usr/lib/python3/dist-packages" "$_site"
+    fi
+    rmdir --ignore-fail-on-non-empty "$pkgdir/usr/lib/python3" 2>/dev/null || true
+  fi
+"""
+s = s.replace(old, new, 1)
+io.open("PKGBUILD", "w", encoding="utf-8").write(s)
+ZZPY
+grep -q 'posix_local scheme installs' PKGBUILD || {
+    echo "meson: the relocation was not inserted" >&2; exit 1; }
+echo "meson: wheel relocated out of /usr/local; STAGE-1 ONLY"
diff --git a/scripts/bootstrap-pacman.sh b/scripts/bootstrap-pacman.sh
index 4a27bbf..6377ee8 100755
--- a/scripts/bootstrap-pacman.sh
+++ b/scripts/bootstrap-pacman.sh
@@ -412,7 +412,34 @@ build_package() {
     # once, rather than in a hook per package. C.UTF-8 and not C: the Arabic
     # and Ukrainian pages must stay valid UTF-8. Arch's own build chroot runs
     # in this locale, so this makes us match it rather than diverge.
+    # DEB_PYTHON_INSTALL_LAYOUT=deb_system, because Debian's python installs
+    # into /usr/local and an Arch package may not ship that tree.
+    #
+    #   $ python3 -c 'import sysconfig; print(sysconfig.get_default_scheme(),
+    #                 sysconfig.get_path("purelib"), sysconfig.get_path("scripts"))'
+    #   posix_local /usr/local/lib/python3.13/dist-packages /usr/local/bin
+    #   $ DEB_PYTHON_INSTALL_LAYOUT=deb_system python3 -c '...'
+    #   deb_system  /usr/lib/python3/dist-packages           /usr/bin
+    #
+    # Without it every wheel-installing PKGBUILD ships /usr/local, and the
+    # filesystem package owns every path in there -- including
+    # usr/local/share/man, which it ships as a SYMLINK. pacman then refuses the
+    # whole transaction:
+    #
+    #   error: failed to commit transaction (conflicting files)
+    #   /usr/local/share/man exists in both 'filesystem' and 'meson'
+    #
+    # Four packages hit this before it was fixed here rather than in each of
+    # them: python-brotli and python-libseccomp (both dropped for other
+    # reasons), meson and python-tqdm. Setting it once covers every python
+    # package, including ones not built yet.
+    #
+    # It does NOT finish the job: deb_system still says dist-packages, and
+    # Arch's python reads site-packages. That last move stays per-package,
+    # because only the packages whose modules are actually IMPORTED on the
+    # target need it -- meson does, and its hook does it.
     LC_ALL=C.UTF-8 \
+    DEB_PYTHON_INSTALL_LAYOUT=deb_system \
     makepkg --nodeps --ignorearch --skippgpcheck --skipchecksums --nocheck \
         -C -f || return 1
     # An exit code is not proof. Only the artefact is.