Ignore more native gems when building gem

brakeman.gemspec

@@ -30,8 +30,8 @@ Gem::Specification.new do |s|
 
     s.files += Dir['bundle/ruby/*/gems/**/*'].reject do |path|
       # Skip unnecessary files in dependencies
-      path =~ /^bundle\/ruby\/\d\.\d\.\d\/gems\/[^\/]+\/(Rakefile|benchmark|bin|doc|example|man|site|spec|test)/ or
-        path.include? '/gems/racc'
+      path =~ %r{^bundle/ruby/\d\.\d\.\d/gems/[^\/]+/(Rakefile|benchmark|bin|doc|example|man|site|spec|test)} or
+        path =~ %r{/gems/(io-console|racc|strscan)/}
     end
 
     # racc is not only a built-in gem, but also has native code which we cannot

build.rb

@@ -1,8 +1,11 @@
 #!/usr/bin/env ruby
+require 'fileutils'
+bundle_exclude = %w[io-console racc strscan]
+
 puts 'Packaging Brakeman gem...'
 
 system 'rm -rf bundle Gemfile.lock brakeman-*.gem' and
-system 'BM_PACKAGE=true bundle install --standalone'
+  system 'BM_PACKAGE=true bundle install --standalone'
 
 abort "No bundle installed" unless Dir.exist? 'bundle'
 
@@ -13,7 +16,9 @@
   f.puts "path = File.expand_path('../..', __FILE__)"
 
   Dir["bundle/ruby/**/lib"].each do |dir|
-    f.puts %Q[$:.unshift "\#{path}/#{dir}"] unless dir.include? 'racc' or dir.include? 'strscan'
+    unless bundle_exclude.any? { |gem_name| dir.include? gem_name }
+      f.puts %Q[$:.unshift "\#{path}/#{dir}"]
+    end
   end
 end