Note: outdated. Check this post instead.

Compiling Ruby on FreeBSD is not quite simple.

• make sure to tell it to also find libraries in /usr/local
• and tell configure script to find OpenSSL in /usr because the later version isn’t quite compatible with latest ruby yet

So here’s the configure line

CFLAGS=-I/usr/local/include \
CPPFLAGS=-I/usr/local/include \
LDFLAGS=-L/usr/local/lib \
./configure --prefix="/opt/ruby23" --disable-install-doc --with-openssl-dir=/usr \
&& make \
&& make install