[FIX] one stray .a file broke every pkg-config lookup

libxslt reported

  configure: error: Package requirements (python-3.14) were not met:
  Package 'python-3.14' not found

with python 3.14.7 installed and /usr/lib/pkgconfig/python-3.14.pc present. The
chain, none of whose links resembles the others:

  binutils installs libiberty.a into /usr/lib64, because s390x's default
  MULTILIB_OSDIRNAME is lib64, creating that path as a REAL directory. meson
  chooses its default libdir by inspecting the system, and 64-bit plus a real
  /usr/lib64 means lib64 -- a symlink does not count, which is why Arch never
  sees this and arch-meson passes no --libdir at all. pkgconf is a meson
  package, so it installed there and COMPILED IN /usr/lib64/pkgconfig as its
  search path. Every .pc in the distribution is in /usr/lib/pkgconfig.

Fixed at all three levels: binutils pinned to --libdir=/usr/lib, the chroot's
arch-meson wrapper pins --libdir lib as a backstop, and the ARTEFACT check --
which said "no Debian multiarch libdir anywhere", truthfully and uselessly --
now also counts paths under usr/lib64.

--- FR ---

libxslt annonçait

  configure: error: Package requirements (python-3.14) were not met:
  Package 'python-3.14' not found

avec python 3.14.7 installé et /usr/lib/pkgconfig/python-3.14.pc bien présent.
La chaîne, dont aucun maillon ne ressemble aux autres :

  binutils dépose libiberty.a dans /usr/lib64, le MULTILIB_OSDIRNAME par défaut
  de s390x, et crée donc ce chemin comme VRAI répertoire. meson choisit son
  libdir par défaut en inspectant le système : 64 bits plus un vrai /usr/lib64
  donne lib64 — un lien ne compte pas, d'où le fait qu'Arch ne voit jamais cela
  et qu'arch-meson ne passe aucun --libdir. pkgconf étant un paquet meson, il
  s'y est installé et a COMPILÉ /usr/lib64/pkgconfig comme chemin de recherche.
  Or tous les .pc de la distribution sont dans /usr/lib/pkgconfig.

Corrigé aux trois niveaux : binutils épinglé à --libdir=/usr/lib, l'enveloppe
arch-meson du chroot épingle --libdir lib en filet, et le test ARTEFACT — qui
répondait « aucun libdir multiarch Debian », véridiquement et inutilement —
compte désormais aussi les chemins sous usr/lib64.

Assisted-by: Claude Opus 5

patches/pkgbuild/binutils.sh

@@ -1,16 +1,45 @@
 #!/usr/bin/env bash
-# binutils: drop the gold linker.
+# binutils: install into /usr/lib, not /usr/lib64.
 #
-#   make[1]: *** [Makefile:6798: all-gold] Error 2
+# THIS IS THE ROOT OF A CHAIN, and the chain is worth writing down because
+# nothing in it looks related to anything else in it:
 #
-# gold is x86-centric, deprecated upstream since binutils 2.44, and it is not
+#   1. On s390x, GCC's and binutils' default MULTILIB_OSDIRNAME is lib64, so
-# built for s390x by any distribution that ships this architecture. Nothing
+#      binutils installs libiberty.a into /usr/lib64 -- creating that directory
-# links with it here: ld.bfd is the linker on Z.
+#      as a REAL directory. On Arch, /usr/lib64 is a SYMLINK to lib.
+#   2. meson chooses its default libdir by looking at the system: 64-bit plus a
+#      real /usr/lib64 means "lib64". A symlink does not count, which is why
+#      Arch never sees this and arch-meson passes no --libdir at all.
+#   3. pkgconf is a meson package, so it installed into /usr/lib64 -- and
+#      COMPILED IN its search path as /usr/lib64/pkgconfig.
+#   4. Every .pc file in the distribution is in /usr/lib/pkgconfig. So every
+#      pkg-config lookup inside the chroot failed. libxslt reported it as
 #
-# Dropped rather than debugged, because fixing gold for s390x would be work
+#        configure: error: Package requirements (python-3.14) were not met:
-# spent on a component upstream is removing.
+#        Package 'python-3.14' not found
+#
+#      with python 3.14.7 installed and /usr/lib/pkgconfig/python-3.14.pc
+#      sitting right there.
+#
+# Step 4 reads as a missing dependency. Step 1 is a linker library nobody
+# thinks about. Fixing only the visible end -- pkgconf's search path -- would
+# leave the real /usr/lib64 there, and the next meson package would land in it.
+#
+# --libdir is set explicitly rather than left to the target default, which is
+# what Arch's layout means: one library directory, /usr/lib, with lib64 as a
+# compatibility symlink.
 set -euo pipefail
-sed -i 's/--enable-gold[^ \\]*//' PKGBUILD
+python3 - <<'ZZPY'
-sed -i 's/^\(\s*\)--enable-gold.*$/\1--disable-gold \\/' PKGBUILD
+import io, re
-grep -q -- '--enable-gold' PKGBUILD && { echo "binutils: gold still enabled" >&2; exit 1; }
+lines = io.open("PKGBUILD", encoding="utf-8").read().split("\n")
-echo "binutils: gold linker disabled (deprecated upstream, absent on s390x)"
+hit = [i for i, l in enumerate(lines) if re.search(r"/configure\b", l) and "#" not in l.split("/configure")[0]]
+assert len(hit) == 1, "binutils: expected one configure call, got %d" % len(hit)
+i = hit[0]
+indent = re.match(r"^[ \t]*", lines[i]).group(0)
+assert lines[i].rstrip().endswith("\\"), "binutils: configure does not continue"
+lines.insert(i + 1, indent + "  --libdir=/usr/lib \\")
+io.open("PKGBUILD", "w", encoding="utf-8").write("\n".join(lines))
+ZZPY
+grep -A1 -E "/configure( |\\\\)" PKGBUILD | grep -q -- '--libdir=/usr/lib' || {
+    echo "binutils: --libdir is not on the configure line" >&2; exit 1; }
+echo "binutils: libdir pinned to /usr/lib (keeps /usr/lib64 a symlink)"

scripts/build-stage2.sh

@@ -164,9 +164,37 @@ EOF
     # files directly, so --nodeps installs exactly these and not a resolved
     # closure -- correct here, since stage 1 already supplied the closure just
     # above.
+    # ONLY WHAT WAS ALREADY THERE. Restoring everything in repo2 fails:
+    #
+    #   :: zlib-ng-compat-2.3.3-1 and zlib-1:1.3.2-3 are in conflict
+    #   stage2: restoring stage-2 output failed
+    #
+    # Both are legitimate stage-2 output -- zlib-ng's PKGBUILD produces
+    # zlib-ng-compat, and zlib is its own package. A REPOSITORY holds both
+    # happily; an installed system cannot, because zlib-ng-compat replaces
+    # zlib. Stage 1 chose zlib for this chroot, and that choice is not stage
+    # 2's to revisit while it is rebuilding.
+    #
+    # So the filter is not a conflict list, which would need extending every
+    # time a package like this appeared. It is the intent stated exactly: put
+    # back the stage-2 build OF WHAT IS INSTALLED. A stage-2 package for
+    # something the chroot does not have was never part of this chroot, and
+    # installing it would quietly grow the build environment past what
+    # CHROOT_PKGS defines.
     shopt -s nullglob
-    local back=("$REPO2"/*.pkg.tar.*)
+    local cand=("$REPO2"/*.pkg.tar.*)
     shopt -u nullglob
+    local back=() inst f pn
+    if [ "${#cand[@]}" -gt 0 ]; then
+        inst=$(sudo pacman --root "$ROOT" --config "$CONF" -Qq 2>/dev/null)
+        for f in "${cand[@]}"; do
+            pn=$(bsdtar -xOf "$f" .PKGINFO 2>/dev/null | sed -n 's/^pkgname = //p')
+            [ -n "$pn" ] || continue
+            grep -qxF "$pn" <<< "$inst" && back+=("$f")
+        done
+        printf '  %s of %s stage-2 package(s) are installed here\n' \
+            "${#back[@]}" "${#cand[@]}"
+    fi
     if [ "${#back[@]}" -gt 0 ]; then
         sudo pacman --root "$ROOT" --config "$CONF" --cachedir "$CACHE" \
             --noconfirm --nodeps -U "${back[@]}" \
@@ -302,10 +330,28 @@ EOC
     sudo install -d -m0755 "$ROOT/usr/local/bin"
     sudo tee "$ROOT/usr/local/bin/arch-meson" > /dev/null <<'EOW'
 #!/usr/bin/env bash
-# stage 2: this chroot has none of Arch's optional documentation tools, so a
+# stage 2, two overrides, both appended because meson honours the last
-# feature that cannot be built should be skipped rather than fatal. Appended,
+# occurrence of an option.
-# because meson honours the last occurrence.
+#
-exec /usr/bin/arch-meson "$@" --auto-features auto
+#   --auto-features auto  This chroot has none of Arch's optional documentation
+#                         tools, so a feature that cannot be built should be
+#                         skipped rather than fatal.
+#
+#   --libdir lib          meson picks its default libdir by inspecting the
+#                         system: 64-bit plus a REAL /usr/lib64 means "lib64".
+#                         On Arch /usr/lib64 is a symlink, so it never triggers
+#                         and arch-meson passes no --libdir at all. In here
+#                         binutils had created a real /usr/lib64 (s390x's
+#                         default MULTILIB_OSDIRNAME), so meson flipped, pkgconf
+#                         installed there, and pkgconf COMPILED IN
+#                         /usr/lib64/pkgconfig as its search path -- while every
+#                         .pc file in the distribution is in /usr/lib/pkgconfig.
+#                         Result: every pkg-config lookup in the chroot failed,
+#                         reported by libxslt as a missing python-3.14 that was
+#                         installed. binutils is pinned too; this is the
+#                         backstop, because the heuristic will fire again the
+#                         moment anything else creates that directory.
+exec /usr/bin/arch-meson "$@" --auto-features auto --libdir lib
 EOW
     sudo chmod 755 "$ROOT/usr/local/bin/arch-meson"
     printf '  arch-meson: wrapped with --auto-features auto\n'
@@ -468,7 +514,18 @@ NOTE
 #   and Ubuntu ships 2.14.5. Ours is 2.15.3 and lives only in here, so this is
 #   the only place libxslt can come from -- built by stage 2, not installed
 #   into it. It has to precede shadow, which the list order does not do.
-STAGE2_FIRST=(texinfo libxslt)
+#
+#   binutils, then pkgconf -- in that order, and both before anything that uses
+#   pkg-config. Stage 1's repository is clean of /usr/lib64; the stage-2
+#   binutils build created it, because s390x's default MULTILIB_OSDIRNAME is
+#   lib64. meson then chose lib64 as its default libdir (it inspects the system,
+#   and a REAL /usr/lib64 flips it -- Arch's is a symlink), pkgconf installed
+#   there, and pkgconf compiled in /usr/lib64/pkgconfig as its search path while
+#   every .pc in the distribution sits in /usr/lib/pkgconfig. Every pkg-config
+#   lookup in the chroot then failed. binutils first so the directory is gone
+#   before pkgconf builds; the arch-meson wrapper pins --libdir lib as the
+#   backstop.
+STAGE2_FIRST=(texinfo binutils pkgconf libxslt)
 
 STAGE2_SKIP_HOOKS=(libgcrypt git meson libarchive)
 

scripts/test-chroot.sh

@@ -96,13 +96,29 @@ else
 fi
 sudo rm -rf "$ROOT.probe"
 
-note "2. ARTEFACT -- host contamination that raises no error"
+note "2. ARTEFACT -- wrong library directories, which raise no error"
+# TWO wrong libdirs, not one.
+#
+# This check was written for Debian's multiarch layout, lib/s390x-linux-gnu,
+# because that was the contamination stage 1 kept producing. It reported "no
+# Debian multiarch libdir anywhere" while binutils and pkgconf were shipping
+# files in /usr/lib64 -- true, and useless, because it was answering a narrower
+# question than the one it appeared to answer.
+#
+# usr/lib64 matters for a reason that is not symmetry. On Arch it is a SYMLINK
+# to lib; a package that ships it as a real directory changes what meson picks
+# as its default libdir, which changed where pkgconf installed, which changed
+# pkgconf's compiled-in search path, which broke every pkg-config lookup in the
+# chroot. One stray .a file at the bottom of that.
 n=0
 for f in "$REPO"/*.pkg.tar.*; do
-    c=$(bsdtar -tf "$f" 2>/dev/null | grep -c 's390x-linux-gnu/')
+    _l=$(bsdtar -tf "$f" 2>/dev/null)
+    c=$(grep -c 's390x-linux-gnu/' <<< "$_l")
     [ "$c" -gt 0 ] && { bad "$(basename "$f"): $c multiarch paths"; n=$((n + 1)); }
+    c=$(grep -c '^usr/lib64/' <<< "$_l")
+    [ "$c" -gt 0 ] && { bad "$(basename "$f"): $c paths under usr/lib64"; n=$((n + 1)); }
 done
-[ "$n" -eq 0 ] && good "no Debian multiarch libdir anywhere"
+[ "$n" -eq 0 ] && good "every library is under usr/lib -- no multiarch, no lib64"
 
 note "3. SONAME -- what binaries ask for versus what the repository ships"
 # Two passes over the packages: collect the soname each shared library