fix(guix): mirror boost unordered patch through local distfiles

steps-guix/improve/local-distfiles-http.sh

@@ -0,0 +1,56 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+distfiles="${DISTFILES:-/external/distfiles}"
+distfiles_http_host="127.0.0.1"
+distfiles_http_port="38445"
+distfiles_http_base_url="http://${distfiles_http_host}:${distfiles_http_port}"
+distfiles_http_pid=""
+distfiles_http_log="/tmp/distfiles-httpd.log"
+
+stop_distfiles_http_server() {
+    if [ -n "${distfiles_http_pid}" ] && kill -0 "${distfiles_http_pid}" >/dev/null 2>&1; then
+        kill "${distfiles_http_pid}" >/dev/null 2>&1 || true
+        wait "${distfiles_http_pid}" >/dev/null 2>&1 || true
+    fi
+}
+
+start_distfiles_http_server() {
+    if [ ! -d "${distfiles}" ]; then
+        echo "Distfiles directory is missing: ${distfiles}" >&2
+        exit 1
+    fi
+
+    if ! command -v python3 >/dev/null 2>&1; then
+        echo "python3 is required to serve local distfiles over HTTP." >&2
+        exit 1
+    fi
+
+    rm -f "${distfiles_http_log}"
+
+    echo "Starting local distfiles HTTP server at ${distfiles_http_base_url}"
+    python3 -m http.server "${distfiles_http_port}" \
+        --bind "${distfiles_http_host}" \
+        --directory "${distfiles}" \
+        >"${distfiles_http_log}" 2>&1 &
+    distfiles_http_pid="$!"
+
+    retry=0
+    while [ "${retry}" -lt 30 ]; do
+        if ! kill -0 "${distfiles_http_pid}" >/dev/null 2>&1; then
+            echo "Local distfiles HTTP server exited unexpectedly." >&2
+            cat "${distfiles_http_log}" >&2 || true
+            exit 1
+        fi
+        if python3 -c "import urllib.request; urllib.request.urlopen('${distfiles_http_base_url}/', timeout=2).read(1)" \
+            >/dev/null 2>&1; then
+            return
+        fi
+        retry=$((retry + 1))
+        sleep 1
+    done
+
+    echo "Timed out waiting for local distfiles HTTP server: ${distfiles_http_base_url}" >&2
+    cat "${distfiles_http_log}" >&2 || true
+    exit 1
+}