As reported in https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=832827
Gnumeric 1.12.31 FTBFS as follows:

> libtool: compile:  cc -Wl,-z,relro -Wl,-z,now -Wl,-O1 -Wl,--as-needed -DHAVE_CONFIG_H -I. -I../.. -DGNOMELOCALEDIR=\"/usr/share/locale\" -I../../src -I../../src -pthread -I/usr/include/librsvg-2.0 -I/usr/include/libgsf-1 -I/usr/include/libxml2 -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libpng16 -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/libgoffice-0.10 -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -Wall -g -Wsign-compare -Wpointer-arith -Wchar-subscripts -Wwrite-strings -Wdeclaration-after-statement -Wnested-externs -Wmissing-noreturn -Werror=missing-prototypes -Werror=implicit-function-declaration -Wmissing-declarations -Wno-pointer-sign -Werror=format-security -Wstrict-prototypes -Wno-error=format-nonliteral -c paradox.c  -fPIC -DPIC -o .libs/paradox.o
> paradox.c: In function 'paradox_file_open':
> paradox.c:65:6: error: implicit declaration of function 'PX_open_gsf' [-Werror=implicit-function-declaration]
>   if (PX_open_gsf (pxdoc, input) < 0) {
>       ^
> paradox.c:65:2: warning: nested extern declaration of 'PX_open_gsf' [-Wnested-externs]
>   if (PX_open_gsf (pxdoc, input) < 0) {
>   ^
> paradox.c: In function 'paradox_file_probe':
> paradox.c:273:12: warning: variable 'pxh' set but not used [-Wunused-but-set-variable]
>   pxhead_t *pxh;
>             ^
> cc1: some warnings being treated as errors