Steps to build nano on a modern macos system (in 2017)

mac-nano-build-setup

##### Prerequisites
#
#  * brew
#  * xcode command line tools
#

### brew installs
brew install automake autoconf pkg-config gettext ncurses

### Add env vars - ~/.bashrc or ~/zshrc if you are a zsh user
export LDFLAGS='-L/usr/local/opt/ncurses/lib'
export CPPFLAGS='-I/usr/local/opt/ncurses/include'

### Add newer tools to path
export PATH=$PATH:/usr/local/opt/gettext/bin
export PATH=/usr/local/opt/texinfo/bin:$PATH
export PATH=/usr/local/opt/ncurses/bin:$PATH