Apparently ginac requires C++11 now, which you need to manually enable with GCC
5.
gcc-6 is now the default and has C++11 enabled by default, so this is no
longer an issue.
Unfortunately the packege now fails to build for a different reason.
https://tests.reproducible-builds.org/debian/rbuild/unstable/amd64/swiginac_1.5.1.1-2.rbuild.log
x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -Wstrict-prototypes
-fno-strict-aliasing -Wdate-time -D_FORTIFY_SOURCE=2 -g
-fdebug-prefix-map=/build/python2.7-oH9M6v/python2.7-2.7.12=.
-fstack-protector-strong -Wformat -Werror=format-security -fPIC
-I/usr/include/python2.7 -c swiginac_wrap.cpp -o
build/temp.linux-x86_64-2.7/swiginac_wrap.o
cc1plus: warning: command line option '-Wstrict-prototypes' is valid for C/ObjC
but not for C++
swiginac_wrap.cpp: In function 'GiNaC::ex GiNaC_basic_normal__SWIG_2(const
GiNaC::basic*, int)':
swiginac_wrap.cpp:5625:41: error: no matching function for call to
'GiNaC::ex::normal(int&)'
return self->eval().normal(level);
^
In file included from /usr/include/ginac/ginac.h:30:0,
from swiginac_wrap.cpp:3305:
/usr/include/ginac/ex.h:186:5: note: candidate: GiNaC::ex GiNaC::ex::normal()
const
ex normal() const;
^~~~~~
/usr/include/ginac/ex.h:186:5: note: candidate expects 0 arguments, 1 provided