From 69978858a4d8a9c34070f96133b8f95737a6505b Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Sun, 20 Feb 2022 17:39:33 +0200
Subject: [PATCH] build: Fix Boost.Process check for Boost 1.73 and older

---
 configure.ac | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/configure.ac b/configure.ac
index c6fde99435f..cc0401eb6db 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1438,9 +1438,13 @@ if test "$use_external_signer" != "no"; then
     ;;
     *)
       AC_MSG_CHECKING([whether Boost.Process can be used])
+      TEMP_LDFLAGS="$LDFLAGS"
+      dnl Boost 1.73 and older require the following workaround.
+      LDFLAGS="$LDFLAGS $PTHREAD_CFLAGS"
       AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <boost/process.hpp>]])],
         [have_boost_process="yes"],
         [have_boost_process="no"])
+      LDFLAGS="$TEMP_LDFLAGS"
       AC_MSG_RESULT([$have_boost_process])
       if test "$have_boost_process" = "yes"; then
         use_external_signer="yes"