GCC behaves differently on Arch Linux

I'm a newbie in Arch Linux. I've tried to compile IRAF package from github and I've got multiple definition error.

/usr/bin/ld: xppcode.o:/home/nastya/iraf/unix/boot/spp/xpp/xppcode.c:109: multiple definition of `errflag'; xppmain.o:/home/nastya/iraf/unix/boot/spp/xpp/xppmain.c:21: first defined herecollect2: error: ld returned 1 exit statusmake: *** [Makefile:19: sysgen] Error 1

My operating system is Manjaro Linux. I use gcc (GCC) 10.1.0.

I've also tried to compile this package on other LINUX distros (on Ubuntu, Debian) and everything was fine.

The problem appears only on Arch. I also tried to use different versions of GCC (5.5 and 7.5.0) and it doesn't solve the problem.

I've also faced this problem earlier during attempt to install another package (GALFIT) on Arch and in that case it perfectly installed on other LINUX distros except Arch.

I appreciate any help and advice.