--- ext/libyajl2/extconf.rb.orig	2021-04-07 03:32:11.000000000 +0000

+++ ext/libyajl2/extconf.rb	2021-10-11 17:10:04.925000000 +0000

@@ -3,20 +3,6 @@ require "rbconfig"

 require "fileutils"

 require "shellwords"

-if ENV["USE_SYSTEM_LIBYAJL2"]

-  File.open("Makefile", "w+") do |f|

-    f.write <<EOF

-# dummy Makefile when we're not really installing

-all:

-\ttrue

-

-install:

-\ttrue

-EOF

-  end

-  exit(0)

-end

-

 module Libyajl2Build

   class BuildError < StandardError; end

@@ -24,6 +10,10 @@ module Libyajl2Build

   PREFIX = File.expand_path("../../../lib/libyajl2/vendored-libyajl2", __FILE__).freeze

+  def self.using_system_libraries?

+    ARGV.include?('--use-system-libraries') || !!ENV['USE_SYSTEM_LIBYAJL2']

+  end

+

   def self.windows?

     !!(RUBY_PLATFORM =~ /mswin|mingw|cygwin|windows/)

   end

@@ -58,8 +48,23 @@ module Libyajl2Build

     $CFLAGS << " -DNDEBUG"

   end

+  def self.make_use_system_makefile

+    File.open("Makefile", "w+") do |f|

+      f.write <<-EOF

+# dummy Makefile when we're not really installing

+all:

+\ttrue

+

+install:

+\ttrue

+      EOF

+    end

+  end

+

   def self.makemakefiles

-    if RUBY_PLATFORM == "java"

+    if using_system_libraries?

+      make_use_system_makefile

+    elsif RUBY_PLATFORM == "java"

       File.open("Makefile", "w+") do |f|

         f.write <<EOF

 CC = gcc