issue #29: Local Homebrew formula for fish 2

.travis.yml

@@ -21,7 +21,7 @@ matrix:
       addons:
         homebrew:
           packages:
-            - 'https://raw.githubusercontent.com/Homebrew/homebrew-core/799fef191cd2beac06930e1d1a8e7f308bd0f4b1/Formula/fish.rb' # 2.7.1
+            - 'test/Homebrew-Formula-fish-2.7.1.rb'
           update: true # TODO: build should be green without, but isn't
     - os: osx
       env: FISH=3

test/Homebrew-Formula-fish-2.7.1.rb

@@ -0,0 +1,60 @@
+class HomebrewFormulaFish271 < Formula
+  desc "User-friendly command-line shell for UNIX-like operating systems"
+  homepage "https://fishshell.com"
+  url "https://github.com/fish-shell/fish-shell/releases/download/2.7.1/fish-2.7.1.tar.gz"
+  mirror "https://fishshell.com/files/2.7.1/fish-2.7.1.tar.gz"
+  sha256 "e42bb19c7586356905a58578190be792df960fa81de35effb1ca5a5a981f0c5a"
+
+  bottle do
+    sha256 "affac16a396410a500241266dbbbd8752562c9b800d9e4f2ef8de279c6fdb6aa" => :high_sierra
+    sha256 "335538a7ea7f9613474f7321af0a1d519b61b0fc4be97a1744a7ea7bef7ff7e3" => :sierra
+    sha256 "463cfa8edc0603761f25e0ba4e49524f69a1d856263d370d1de5fb8698dd5ccf" => :el_capitan
+  end
+
+  head do
+    url "https://github.com/fish-shell/fish-shell.git", :shallow => false
+
+    depends_on "autoconf" => :build
+    depends_on "automake" => :build
+    depends_on "doxygen" => :build
+  end
+
+  depends_on "pcre2"
+
+  def install
+    system "autoreconf", "--no-recursive" if build.head?
+
+    # In Homebrew's 'superenv' sed's path will be incompatible, so
+    # the correct path is passed into configure here.
+    args = %W[
+      --prefix=#{prefix}
+      --with-extra-functionsdir=#{HOMEBREW_PREFIX}/share/fish/vendor_functions.d
+      --with-extra-completionsdir=#{HOMEBREW_PREFIX}/share/fish/vendor_completions.d
+      --with-extra-confdir=#{HOMEBREW_PREFIX}/share/fish/vendor_conf.d
+      SED=/usr/bin/sed
+    ]
+    system "./configure", *args
+    system "make", "install"
+  end
+
+  def caveats; <<~EOS
+    You will need to add:
+      #{HOMEBREW_PREFIX}/bin/fish
+    to /etc/shells.
+
+    Then run:
+      chsh -s #{HOMEBREW_PREFIX}/bin/fish
+    to make fish your default shell.
+    EOS
+  end
+
+  def post_install
+    (pkgshare/"vendor_functions.d").mkpath
+    (pkgshare/"vendor_completions.d").mkpath
+    (pkgshare/"vendor_conf.d").mkpath
+  end
+
+  test do
+    system "#{bin}/fish", "-c", "echo"
+  end
+end