do-agent: Build fails on FreeBSD

Running make build fails on FreeBSD nodes. Here are the errors shown on my node which is running FreeBSD 10.3.

root@bsd1:/usr/src/do-agent # make build
make: "/usr/src/do-agent/Makefile" line 8: Missing dependency operator
make: "/usr/src/do-agent/Makefile" line 10: Need an operator
make: "/usr/src/do-agent/Makefile" line 12: Need an operator
make: "/usr/src/do-agent/Makefile" line 82: Missing dependency operator
make: "/usr/src/do-agent/Makefile" line 83: warning: duplicate script for target "ifeq" ignored
make: "/usr/src/do-agent/Makefile" line 9: warning: using previous script for "ifeq" defined here
make: "/usr/src/do-agent/Makefile" line 83: warning: duplicate script for target "("",)" ignored
make: "/usr/src/do-agent/Makefile" line 9: warning: using previous script for "("",)" defined here
make: "/usr/src/do-agent/Makefile" line 84: Need an operator
make: "/usr/src/do-agent/Makefile" line 86: Need an operator
make: Fatal errors encountered -- cannot continue
make: stopped in /usr/src/do-agent