fix(guix-bootstrap): export bootstrap exec seeds via improve

steps-guix/improve/bootstrap-exec-xz-i686-linux.sh

@@ -1,15 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-3.0-or-later
-
-set -e
-
-dist="${DISTFILES:-/external/distfiles}"
-xz_src="/bootstrap-seeds/xz-5.0.6/bin/xz"
-xz_dst="${dist}/bootstrap-exec-xz-i686-linux"
-
-if [ ! -x "${xz_src}" ]; then
-    echo "Missing required bootstrap seed executable: ${xz_src}" >&2
-    exit 1
-fi
-
-install -D -m 0755 "${xz_src}" "${xz_dst}"

steps-guix/improve/bootstrap-execs-i686-linux.sh

@@ -0,0 +1,23 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+set -e
+
+dist="${DISTFILES:-/external/distfiles}"
+
+install_exec() {
+    local src="$1"
+    local dst="$2"
+
+    if [ ! -x "${src}" ]; then
+        echo "Missing required bootstrap seed executable: ${src}" >&2
+        exit 1
+    fi
+
+    install -D -m 0755 "${src}" "${dist}/${dst}"
+}
+
+install_exec /bootstrap-seeds/bash-5.3-1/bin/bash bootstrap-exec-bash-i686-linux
+install_exec /bootstrap-seeds/coreutils-8.30/bin/mkdir bootstrap-exec-mkdir-i686-linux
+install_exec /bootstrap-seeds/tar-1.30/bin/tar bootstrap-exec-tar-i686-linux
+install_exec /bootstrap-seeds/xz-5.0.6/bin/xz bootstrap-exec-xz-i686-linux

steps-guix/manifest

@@ -59,9 +59,9 @@ build: bzip2-1.0.6
 build: patch-2.7.6
 build: bash-5.3-1
 build: static-binaries-0-i686-linux
-# Build legacy xz seed, then export bootstrap-exec-xz-i686-linux
+# Build legacy xz seed, then export bootstrap exec seeds
 build: xz-5.0.6
-improve: bootstrap-exec-xz-i686-linux
+improve: bootstrap-execs-i686-linux
 # Build guile-static-stripped-2.0.9-i686-linux.tar.xz
 build: libunistring-1.4.1-guix
 build: gc-8.2.12-guix

steps-guix/static-binaries-0-i686-linux/pass1.sh

@@ -33,9 +33,6 @@ src_compile() {
 
     seed_make_repro_tar_xz "${stage}" "${dist}/static-binaries-0-i686-linux.tar.xz"
 
-    seed_install_exec "${stage}/bin/bash" "${dist}/bootstrap-exec-bash-i686-linux"
-    seed_install_exec "${stage}/bin/mkdir" "${dist}/bootstrap-exec-mkdir-i686-linux"
-    seed_install_exec "${stage}/bin/tar" "${dist}/bootstrap-exec-tar-i686-linux"
 }
 
 src_install() {