Brew formula that applies a quick patch to the fish source before installing. This patch fixes the "5 second freeze" fish on osx sometimes has.

fishpatch.rb

require 'formula'

class Fishpatch < Formula
  url 'http://downloads.sourceforge.net/project/fish/fish/1.23.1/fish-1.23.1.tar.bz2'
  homepage 'http://fishshell.org/'
  md5 'ead6b7c6cdb21f35a3d4aa1d5fa596f1'

  depends_on 'readline'
  skip_clean 'share/doc'

  def install
    system "sed -e 's/tv.tv_sec=5/tv.tv_sec=0/g' -e 's/tv.tv_usec=0/tv.tv_usec=10000/g' proc.c > temp.c"
    system "mv temp.c proc.c"
    system "./configure", "--prefix=#{prefix}", "--without-xsel"
    system "make install"
  end

  def caveats
    "You will need to add #{HOMEBREW_PREFIX}/bin/fish to /etc/shells\n"+
    "Run `chsh -s #{HOMEBREW_PREFIX}/bin/fish' to make fish your default shell."
  end
end

To install the patched fish, follow these steps:

1. if you have fish installed already, uninstall it:
   $ brew uninstall
2. download the script above and save it as /usr/local/Library/Formula/fispatch.rb
3. install patched fish:
   $ brew install fishpatch

The actual fix was found in benhoskings' fish clone: https://github.com/benhoskings/fish