Makefile.am error: '#' comment at start of rule is unportable

Seeing this for iptables lzo-2.10 and python3 during building process...

make[5]: Entering directory '/home/user/owrtr7500v2/master/build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/linux-ipq806x_generic/iptables-1.8.4'
Makefile.am:303: error: '#' comment at start of rule is unportable
Makefile.am:304: error: '#' comment at start of rule is unportable

make[5]: Entering directory '/home/user/owrtr7500v2/master/build_dir/target-arm_cortex-a15+neon-vfpv4_musl_eabi/lzo-2.10'
Makefile.am:304: error: '#' comment at start of rule is unportable
make[4]: [Makefile:280: libhogweed.so] Error 1 (ignored)

make[3]: Entering directory '/home/user/owrtr7500v2/master/feeds/packages/lang/python/python3'
Makefile.am:304: error: '#' comment at start of rule is unportable