I tried this on a few different systems and fails seems to be the same. A bunch of warnings and then this final error:
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc: In member function \u2018void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp, _Alloc>::iterator, _Args&& ...) [with _Args = {nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long long int, long long unsigned int, double, std::allocator, nlohmann::adl_serializer>}; _Tp = nlohmann::basic_json<>; _Alloc = std::allocator<nlohmann::basic_json<> >]\u2019:
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc:394:7: note: parameter passing for argument of type \u2018std::vector<nlohmann::basic_json<>, std::allocator<nlohmann::basic_json<> > >::iterator {aka __gnu_cxx::__normal_iterator<nlohmann::basic_json<>*, std::vector<nlohmann::basic_json<>, std::allocator<nlohmann::basic_json<> > > >}\u2019 changed in GCC 7.1
vector<_Tp, _Alloc>::
^~~~~~~~~~~~~~~~~~~
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc: In member function \u2018void nlohmann::detail::parser<BasicJsonType>::parse_internal(bool, BasicJsonType&) [with BasicJsonType = nlohmann::basic_json<>]\u2019:
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc:105:21: note: parameter passing for argument of type \u2018__gnu_cxx::__normal_iterator<nlohmann::basic_json<>*, std::vector<nlohmann::basic_json<>, std::allocator<nlohmann::basic_json<> > > >\u2019 changed in GCC 7.1
_M_realloc_insert(end(), std::forward<_Args>(__args)...);
~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CXX libipmi20_la-ipmisensor.lo
CXX libipmi20_la-storageaddsel.lo
CXX libipmi20_la-transporthandler.lo
In file included from /esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/vector:69:0,
from /esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/experimental/bits/fs_path.h:39,
from /esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/experimental/filesystem:39,
from transporthandler.cpp:11:
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc: In member function \u2018void std::vector<_Tp, _Alloc>::_M_realloc_insert(std::vector<_Tp, _Alloc>::iterator, _Args&& ...) [with _Args = {nlohmann::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long long int, long long unsigned int, double, std::allocator, nlohmann::adl_serializer>}; _Tp = nlohmann::basic_json<>; _Alloc = std::allocator<nlohmann::basic_json<> >]\u2019:
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc:394:7: note: parameter passing for argument of type \u2018std::vector<nlohmann::basic_json<>, std::allocator<nlohmann::basic_json<> > >::iterator {aka __gnu_cxx::__normal_iterator<nlohmann::basic_json<>*, std::vector<nlohmann::basic_json<>, std::allocator<nlohmann::basic_json<> > > >}\u2019 changed in GCC 7.1
vector<_Tp, _Alloc>::
^~~~~~~~~~~~~~~~~~~
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc: In member function \u2018void nlohmann::detail::parser<BasicJsonType>::parse_internal(bool, BasicJsonType&) [with BasicJsonType = nlohmann::basic_json<>]\u2019:
/esw/san5/openbmc/sdk/witherspoon/latest/sysroots/armv6-openbmc-linux-gnueabi/usr/include/c++/7.3.0/bits/vector.tcc:105:21: note: parameter passing for argument of type \u2018__gnu_cxx::__normal_iterator<nlohmann::basic_json<>*, std::vector<nlohmann::basic_json<>, std::allocator<nlohmann::basic_json<> > > >\u2019 changed in GCC 7.1
_M_realloc_insert(end(), std::forward<_Args>(__args)...);
~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CXX libipmi20_la-globalhandler.lo
CXX libipmi20_la-groupext.lo
CXX libipmi20_la-utils.lo
CXX libipmi20_la-selutility.lo
CXX libipmi20_la-ipmi_fru_info_area.lo
CXX libipmi20_la-read_fru_data.lo
CXX libipmi20_la-sensordatahandler.lo
CXX libipmi20_la-sensor-gen.lo
sensor-gen.cpp:147:1: error: could not convert \u2018{{96, {7, "/org/open_power/control/occ0", "org.open_power.OCC.Status", 111, 1, 0, 0, 0, ipmi::sensor::set::assertion, ipmi::sensor::get::assertion, (ipmi::sensor::Mutability)1, {{"org.open_power.OCC.Status", {{"OccActive", {<brace-enclosed initializer list>(), {{6, {NONE, false, true}}}}}}}}}}, {97, {4, "/system/chassis/motherboard/dimm1", "xyz.openbmc_project.Inventory.Manager", 111, 1, 0, 0, 0, ipmi::sensor::notify::assertion, ipmi::sensor::inventory::get::assertion, (ipmi::sensor::Mutability)1, {{"xyz.openbmc_project.State.Decorator.OperationalStatus", {{"Functional", {{{4, {false, true}}}, {{6, {NONE, true, false}}}}}}}, {"xyz.openbmc_project.Inventory.Item", {{"Present", {<brace-enclosed initializer list>(), {{4, {NONE, false, true}}}}}}}}}}, {98, {195, "/xyz/openbmc_project/state/host1", "xyz.openbmc_project.Control.Boot.RebootAttempts", 111, 1, 0, 0, 0, readingAssertion<uint32_t>, readingAssertion<uint32_t>, (ipmi::sensor::Mutability)1, {{"xyz.openbmc_project.Control.Boot.RebootAttempts", {{"AttemptsLeft", {<brace-enclosed initializer list>(), {{255, <brace-enclosed initializer list>()}}}}}}}}}, {99, {195, "/xyz/openbmc_project/state/host0", "xyz.openbmc_project.Control.Boot.RebootAttempts", 111, 1, 0, 0, 0, readingAssertion<uint32_t>, readingAssertion<uint32_t>, (ipmi::sensor::Mutability)1, {{"xyz.openbmc_project.Control.Boot.RebootAttempts", {{"AttemptsLeft", {<brace-enclosed initializer list>(), {{255, <brace-enclosed initializer list>()}}}}}}}}}, {84, {7, "/system/chassis/motherboard/cpu0/core22", "xyz.openbmc_project.Inventory.Manager", 111, 1, 0, 0, 0, ipmi::sensor::notify::assertion, ipmi::sensor::inventory::get::assertion, (ipmi::sensor::Mutability)1, {{"xyz.openbmc_project.State.Decorator.OperationalStatus", {{"Functional", {{{7, {true, false}}}, {{8, {NONE, false, true}}}}}}}, {"xyz.openbmc_project.Inventory.Item", {{"Present", {<brace-enclosed initializer list>(), {{7, {DEASSERT, true, false}}}}}}}}}}, {208, {1, "/xyz/openbmc_project/sensors/temperature/fleeting0", "xyz.openbmc_project.Sensor.Value", 1, 511, 0, 0, 0, readingData<int64_t>, readingData<int64_t>, ipmi::sensor::operator|((ipmi::sensor::Mutability)2, (ipmi::sensor::Mutability)1), {{"xyz.openbmc_project.Sensor.Value", {{"Value", {<brace-enclosed initializer list>(), {{255, <brace-enclosed initializer list>()}}}}}}}}}}\u2019 from \u2018<brace-enclosed initializer list>\u2019 to \u2018const IdInfoMap {aka const std::map<unsigned char, ipmi::sensor::Info>}\u2019
};
^
make[2]: *** [libipmi20_la-sensor-gen.lo] Error 1
make[2]: Leaving directory `/esw/san5/andrewg/Code/phosphor-host-ipmid'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/esw/san5/andrewg/Code/phosphor-host-ipmid'
make: *** [all] Error 2
[andrewg@gfwa180 phosphor-host-ipmid]$