nmap vs brew on osx

So recently I tried installing nmap primarily for discovering a lazy way of controlling Minecraft on our Raspberry Pi over the home LAN.

Naturally it didn't work first time.
Naturally I spent hours trawling stack overflow and the only matches for my error messages were about  Ruby, which had nothing to do with what I wanted.

Finally found the solution that worked, its here:

The error:

~:-> nmap
dyld: Library not loaded: @@HOMEBREW_PREFIX@@/opt/openssl/lib/libssl.1.0.0.dylib
  Referenced from: /usr/local/bin/nmap
  Reason: image not found

Identify the problem:

  ~ : ->otool -L /usr/local/bin/nmap
/usr/local/bin/nmap:
        /usr/lib/libpcap.A.dylib (compatibility version 1.0.0, current version 1.0.0)
        @@HOMEBREW_PREFIX@@/opt/openssl/lib/libssl.1.0.0.dylib (compatibility version 1.0.0, current version 1.0.0)
 @@HOMEBREW_PREFIX@@/opt/openssl/lib/libcrypto.1.0.0.dylib (compatibility version 1.0.0, current version 1.0.0)
        /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 159.1.0)
        /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 52.0.0)

Now to correct the two HOMEBREW_PREFIX paths:

~ : ->sudo install_name_tool -change @@HOMEBREW_PREFIX@@/opt/openssl/lib/libssl.1.0.0.dylib/usr/local/opt/openssl/lib/libssl.1.0.0.dylib /usr/local/bin/nmap

~ : ->sudo install_name_tool -change @@HOMEBREW_PREFIX@@/opt/openssl/lib/libcrypto.1.0.0.dylib /usr/local/opt/openssl/lib/libcrypto.1.0.0.dylib /usr/local/bin/nmap

Then run otool again, and the homebrew_prefix variables should have been replaced with absolute paths. This fixed nmap for me!

Also useful, but not *the* fix:

brew --config
brew doctor
brew update

This link was the one that helped the most

http://superuser.com/questions/282450/where-do-i-set-dyld-library-path-on-mac-os-x-and-is-it-a-good-idea