Missing libm link library for vtkkissfft
kissfft uses sincos and sqrt and thus should be linked with libm under "UNIX".
[ 40s] /var/lib/build/ccache/bin/gcc -fPIC -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector-strong -funwind-tables -fasynchronous-unwind-tables -fstack-clash-protection -Werror=return-type -flto=auto -g -DNDEBUG -O2 -g -DNDEBUG -Wl,-lc -flto=auto -Wl,--as-needed -Wl,--no-undefined -Wl,-z,now -shared -Wl,-soname,libvtkkissfft.so.1 -o ../../../lib64/libvtkkissfft.so.9.1.0 CMakeFiles/kissfft.dir/kiss_fft.c.o CMakeFiles/kissfft.dir/tools/kiss_fastfir.c.o CMakeFiles/kissfft.dir/tools/kiss_fftnd.c.o CMakeFiles/kissfft.dir/tools/kiss_fftndr.c.o CMakeFiles/kissfft.dir/tools/kiss_fftr.c.o
[ 40s] /usr/lib64/gcc/x86_64-suse-linux/11/../../../../x86_64-suse-linux/bin/ld: /tmp/ccwYefBl.ltrans0.ltrans.o: in function `vtkkissfft_fft_alloc':
[ 40s] /home/abuild/rpmbuild/BUILD/VTK-9.1.0/ThirdParty/kissfft/vtkkissfft/kiss_fft.c:351: undefined reference to `sincos'
[ 40s] /usr/lib64/gcc/x86_64-suse-linux/11/../../../../x86_64-suse-linux/bin/ld: /home/abuild/rpmbuild/BUILD/VTK-9.1.0/ThirdParty/kissfft/vtkkissfft/kiss_fft.c:307: undefined reference to `sqrt'
[ 40s] /usr/lib64/gcc/x86_64-suse-linux/11/../../../../x86_64-suse-linux/bin/ld: /tmp/ccwYefBl.ltrans0.ltrans.o: in function `vtkkissfft_fftr_alloc':
[ 40s] /home/abuild/rpmbuild/BUILD/VTK-9.1.0/ThirdParty/kissfft/vtkkissfft/tools/kiss_fftr.c:51: undefined reference to `sincos'