How to compile tarsnap on your MAC OS

tarsnap_install.sh

# Install OpenSSL
brew install openssl

# Make sure you add openssl to your shell :

ZSH:  echo 'export PATH="/usr/local/opt/openssl/bin:$PATH"' >> ~/.zshrc
Bash: echo 'export PATH="/usr/local/opt/openssl/bin:$PATH"' >> ~/.bashrc

# and then export the following environment variables:
    export LDFLAGS=-L/usr/local/opt/openssl/lib
    export CPPFLAGS=-I/usr/local/opt/openssl/include
# Note: For pkg-config to find this software you may need to set:
    PKG_CONFIG_PATH: /usr/local/opt/openssl/lib/pkgconfig

# and run source command

$ source ~/.zshrc
$ source ~/.bashrc

# then install autoconf, automake 
$ brew install autoconf
$ brew install automake

# Checkout the git code:
    https://github.com/Tarsnap/tarsnap

# change your current directory to: tarsnap

autoreconf -i
./configure
make
make install