Not able to compile C++ program with libbgi.a on Netbeans (Cygwin)

Question

I am trying to compile an old graphics.h based animation program. I downloaded libbgi.a and its associated header files from WinBGIm and followed instructions from here (It was for Codeblocks but I tried to follow similar steps for Netbeans). When I tried to build it shows error during linking (as below).

Please tell me what's wrong?

The libbgi.a is in /lib/ folder and its associated header files are in /usr/include folder.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <graphics.h>
#include <string.h>

int main() {
    int gdriver = DETECT, gmode, errorcode;
    initgraph(&gdriver, &gmode, (char*) "");
    errorcode = graphresult();
    /* an error occurred */
    if (errorcode != grOk) {
       printf("Graphics error: %s\n", grapherrormsg(errorcode));
       printf("Press any key to halt:");
       getch();
       exit(1);
    }

    getch();
    closegraph();
    return 0;
}

Error message:

g++ -m64    -o dist/Debug/Cygwin-Windows/bouncingballbgi build/Debug/Cygwin-Windows/bouncing_ball.o /cygdrive/D/softwares/cygwin64/lib/libbgi.a -lbgi -lgdi32 -lcomdlg32 -luuid -loleaut32 -lole32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /lib/../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /lib/../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /lib/../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/../lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/libbgi.a when searching for -lbgi
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lbgi
collect2: error: ld returned 1 exit status

Edit:

Following the below steps:

mkdir junk; cd junk
ar x /usr/lib/libbgi.a
file *.o

I got this output:

dibutil.o:   Intel 80386 COFF object file, no line number info, not stripped, 4 sections, symbol offset=0x1b7c, 44 symbols
drawing.o:   Intel 80386 COFF object file, no line number info, not stripped, 6 sections, symbol offset=0x5590, 126 symbols
file.o:      Intel 80386 COFF object file, no line number info, not stripped, 4 sections, symbol offset=0x6fc, 30 symbols
misc.o:      Intel 80386 COFF object file, no line number info, not stripped, 6 sections, symbol offset=0x1840, 83 symbols
mouse.o:     Intel 80386 COFF object file, no line number info, not stripped, 4 sections, symbol offset=0x448, 21 symbols
palette.o:   Intel 80386 COFF object file, no line number info, not stripped, 3 sections, symbol offset=0x116, 16 symbols
text.o:      Intel 80386 COFF object file, no line number info, not stripped, 8 sections, symbol offset=0x1c0c, 85 symbols
winbgi.o:    Intel 80386 COFF object file, no line number info, not stripped, 16 sections, symbol offset=0x319c, 128 symbols
winthread.o: Intel 80386 COFF object file, no line number info, not stripped, 27 sections, symbol offset=0x84fe, 130 symbols

Edit2:

On compiling the code with 32-bit mode (-m32 flag), I got these errors:

g++ -m32    -o dist/Debug/Cygwin-Windows/bouncingballbgi build/Debug/Cygwin-Windows/bouncing_ball.o /cygdrive/D/softwares/cygwin64/lib/libbgi.a -lbgi -lgdi32 -lcomdlg32 -luuid -loleaut32 -lole32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libgdi32.a when searching for -lgdi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libgdi32.a when searching for -lgdi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libgdi32.a when searching for -lgdi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lgdi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libcomdlg32.a when searching for -lcomdlg32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libcomdlg32.a when searching for -lcomdlg32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libcomdlg32.a when searching for -lcomdlg32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lcomdlg32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libuuid.a when searching for -luuid
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libuuid.a when searching for -luuid
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libuuid.dll.a when searching for -luuid
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libuuid.a when searching for -luuid
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libuuid.dll.a when searching for -luuid
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -luuid
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/liboleaut32.a when searching for -loleaut32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/liboleaut32.a when searching for -loleaut32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/liboleaut32.a when searching for -loleaut32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -loleaut32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libole32.a when searching for -lole32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libole32.a when searching for -lole32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libole32.a when searching for -lole32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lole32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libstdc++.dll.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libstdc++.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libstdc++.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libstdc++.dll.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libstdc++.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libstdc++.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libstdc++.dll.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libstdc++.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libstdc++.dll.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libstdc++.a when searching for -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lstdc++
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libcygwin.a when searching for -lcygwin
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libcygwin.a when searching for -lcygwin
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../libcygwin.a when searching for -lcygwin
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lcygwin
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libadvapi32.a when searching for -ladvapi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libadvapi32.a when searching for -ladvapi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libadvapi32.a when searching for -ladvapi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -ladvapi32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libshell32.a when searching for -lshell32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libshell32.a when searching for -lshell32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libshell32.a when searching for -lshell32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lshell32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libuser32.a when searching for -luser32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libuser32.a when searching for -luser32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libuser32.a when searching for -luser32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -luser32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libkernel32.a when searching for -lkernel32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libkernel32.a when searching for -lkernel32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/w32api/libkernel32.a when searching for -lkernel32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lkernel32
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc_s.dll.a when searching for -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lgcc_s
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0//libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-pc-cygwin/6.4.0/libgcc.a when searching for -lgcc
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld: cannot find -lgcc
collect2: error: ld returned 1 exit status

Answer 1

Although gcc's -m32 ([GNU.GCC]: x86 Options) works well, on Cygwin there are some issues.

Just to recap, you're trying to build a 32bit application (using some 32bit built static lib) on a 64bit Cygwin.
Even if there is a series of steps that would allow you to achieve your goal, the simplest way is to install the 32bit gcc toolchain.

Example:

[cfati@cfati-5510-0:/cygdrive/e/Work/Dev/StackOverflow/q057461809]> ~/sopr.sh
*** Set shorter prompt to better fit when pasted in StackOverflow (or other) pages ***

[064bit prompt]> uname -a
CYGWIN_NT-10.0 cfati-5510-0 3.0.7(0.338/5/3) 2019-04-30 18:08 x86_64 Cygwin
[064bit prompt]>
[064bit prompt]> which g++
/usr/bin/g++
[064bit prompt]> GPPS="/usr/bin/g++ /usr/bin/x86_64-pc-cygwin-g++.exe /usr/bin/i686-pc-cygwin-g++.exe"
[064bit prompt]> echo ${GPPS}
/usr/bin/g++ /usr/bin/x86_64-pc-cygwin-g++.exe /usr/bin/i686-pc-cygwin-g++.exe
[064bit prompt]>
[064bit prompt]> for GPP in ${GPPS}; do ll ${GPP}; done
-rwxr-xr-x 4 cfati None 936467 Dec  9  2018 /usr/bin/g++
-rwxr-xr-x 4 cfati None 936467 Dec  9  2018 /usr/bin/x86_64-pc-cygwin-g++.exe
-rwxr-xr-x 2 cfati None 931347 Apr 17  2018 /usr/bin/i686-pc-cygwin-g++.exe
[064bit prompt]>
[064bit prompt]> for GPP in ${GPPS}; do md5sum ${GPP}; done
71b02af056efb46a3e66279ce80e554f */usr/bin/g++
71b02af056efb46a3e66279ce80e554f */usr/bin/x86_64-pc-cygwin-g++.exe
4642d1d76335bf5394e7c0917acf13d0 */usr/bin/i686-pc-cygwin-g++.exe
[064bit prompt]>
[064bit prompt]> for GPP in ${GPPS}; do cygcheck -f ${GPP}; done
gcc-g++-7.4.0-1
gcc-g++-7.4.0-1
cygwin32-gcc-g++-7.3.0-1

As seen, g++ and x86_64-pc-cygwin-g++ are the same (normally, the former should be a symlink to the latter), while i686-pc-cygwin-g++ is what you need.
Install its package (cygwin32-gcc-g++-*) and all its dependencies (as shown below) and use that executable when attempting to build.

As an alternative, you could install the 32bit Cygwin (the 2 variants can happily coexist on the same machine - I have them both installed on my laptop) and try to build there.

For more details on 64bit / 32bit compatibilities, check [SO]: Can you run a 32 bit Cygwin application in a 64 bit installation? (@CristiFati's answer).