Adding a script to spawn MacOS's build environment.

tools/distrib/build_ruby_environment_macos.sh

+#!/bin/bash
+# Copyright 2015-2016, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+set -ex
+
+CROSS_RUBY=`mktemp`
+
+curl https://raw.githubusercontent.com/rake-compiler/rake-compiler/v0.9.5/tasks/bin/cross-ruby.rake > $CROSS_RUBY
+
+patch $CROSS_RUBY << EOF
+--- cross-ruby.rake	2016-02-05 16:26:53.000000000 -0800
++++ cross-ruby.rake.patched	2016-02-05 16:27:33.000000000 -0800
+@@ -133,7 +133,8 @@
+     "--host=#{MINGW_HOST}",
+     "--target=#{MINGW_TARGET}",
+     "--build=#{RUBY_BUILD}",
+-    '--enable-shared',
++    '--enable-static',
++    '--disable-shared',
+     '--disable-install-doc',
+     '--without-tk',
+     '--without-tcl'
+EOF
+
+MAKE="make -j8"
+
+for v in 2.3.0 2.2.2 2.1.6 2.0.0-p645 ; do
+  rake -f $CROSS_RUBY cross-ruby VERSION=$v HOST=x86_64-darwin11
+done
+
+sed 's/x86_64-darwin-11/universal-darwin/' ~/.rake-compiler/config.yaml > $CROSS_RUBY
+mv $CROSS_RUBY > ~/.rake-compiler/config.yaml