g++ -DHAVE_CONFIG_H -I. -I. -I. -I../src -I/usr/include/openbabel -O2 -march=athlon-mp -fomit-frame-pointer -fstack-protector -pipe -MT eng1_qm_mpqc.lo -MD -MP -MF .deps/eng1_qm_mpqc.Tpo -c eng1_qm_mpqc.cpp -fPIC -DPIC -o .libs/eng1_qm_mpqc.o
In file included from /usr/lib/gcc/i686-pc-linux-gnu/3.4.4/include/g++-v3/backward/strstream:51,
from eng1_qm_mpqc.cpp:14:
/usr/lib/gcc/i686-pc-linux-gnu/3.4.4/include/g++-v3/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header. Please consider using one of the 32 headers found in section 17.4.1.2 of the C++ standard. Examples include substituting the <X> header for the <X.h> header for C++ includes, or <iostream> instead of the deprecated header <iostream.h>. To disable this warning use -Wno-deprecated.
eng1_qm_mpqc.cpp: In constructor `eng1_qm_mpqc::eng1_qm_mpqc(setup*, i32u, i32u)':
eng1_qm_mpqc.cpp:61: error: no matching function for call to `sc::PrefixKeyVal::PrefixKeyVal(const char[5], sc::ParsedKeyVal*)'
/usr/include/util/keyval/keyval.h:488: note: candidates are: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, const char*, int, int, int, int)
/usr/include/util/keyval/keyval.h:487: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, const char*, int, int, int)
/usr/include/util/keyval/keyval.h:486: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, const char*, int, int)
/usr/include/util/keyval/keyval.h:485: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, const char*, int)
/usr/include/util/keyval/keyval.h:484: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, const char*)
/usr/include/util/keyval/keyval.h:483: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, int, int, int, int)
/usr/include/util/keyval/keyval.h:482: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, int, int, int)
/usr/include/util/keyval/keyval.h:481: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, int, int)
/usr/include/util/keyval/keyval.h:480: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::Ref<sc::KeyVal>&, int)
/usr/include/util/keyval/keyval.h:471: note: sc::PrefixKeyVal::PrefixKeyVal(const sc::PrefixKeyVal&)
make[2]: *** [eng1_qm_mpqc.lo] Error 1
make[2]: Leaving directory `/var/tmp/portage/libghemical-1.91/work/libghemical-1.91/src'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/var/tmp/portage/libghemical-1.91/work/libghemical-1.91/src'
make: *** [all-recursive] Error 1

It fails against 2.3.0 but builds successfully against 2.2.3.