Combination of:
https://github.com/tsuna/boost.m4/commit/8d9ceb2dc54587aa1cace4bc0932a804b0538d36
https://github.com/tsuna/boost.m4/commit/c88f9d1d27707d85ba39fbaeedddddd505e76e6c

diff -u a/build-aux/boost.m4 b/build-aux/boost.m4
--- a/build-aux/boost.m4
+++ b/build-aux/boost.m4
@@ -1332,11 +1332,16 @@
 # --------------------------------
 # Look for Boost.System.  For the documentation of PREFERRED-RT-OPT, see the
 # documentation of BOOST_FIND_LIB above.  This library was introduced in Boost
-# 1.35.0.
+# 1.35.0 and is header only since 1.70.
 BOOST_DEFUN([System],
-[BOOST_FIND_LIB([system], [$1],
+[
+if test $boost_major_version -ge 170; then
+  BOOST_FIND_HEADER([boost/system/error_code.hpp])
+else
+  BOOST_FIND_LIB([system], [$1],
                 [boost/system/error_code.hpp],
                 [boost::system::error_code e; e.clear();], [], [], [$2])
+fi
 ])# BOOST_SYSTEM