diff --git a/.gitignore b/.gitignore
index 188a4c4..49d3d54 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,3 +25,4 @@
 /config/config.rb
 /vendor/
 /.bundle/
+/pkg/
diff --git a/lib/download.rb b/lib/download.rb
index 5777e64..6d1b7fb 100644
--- a/lib/download.rb
+++ b/lib/download.rb
@@ -7,6 +7,26 @@
 require_relative '../config/config'
 require_relative 'package'
 require 'net/http'
+require 'pathname'
+
+module SlackBuilder
+  extend Rake::FileUtilsExt
+
+  def self.clone(repo, package, tag_prefix = 'v')
+    repository = Pathname.new('pkg') + package.name_version
+
+    if repository.directory?
+      sh 'git', '-C', repository.to_path, 'remote', 'update', '--prune'
+    else
+      sh 'git', 'clone', repo, repository.to_path
+    end
+
+    sh 'git', '-C', repository.to_path, 'checkout', "#{tag_prefix}#{package.version}"
+    sh 'git', '-C', repository.to_path, 'submodule', 'update', '--init', '--recursive'
+
+    repository
+  end
+end
 
 def write_download(target, response)
   checksum = Digest::MD5.new
diff --git a/lib/package.rb b/lib/package.rb
index ab31ce6..39a36c6 100644
--- a/lib/package.rb
+++ b/lib/package.rb
@@ -17,6 +17,10 @@ class Package
   def name
     File.basename @path
   end
+
+  def name_version
+    "#{name}-#{@version}"
+  end
 end
 
 class Download
diff --git a/rakelib/hhvm.rake b/rakelib/hhvm.rake
new file mode 100644
index 0000000..cb6fc16
--- /dev/null
+++ b/rakelib/hhvm.rake
@@ -0,0 +1,67 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+# frozen_string_literal: true
+
+namespace :hhvm do
+  desc 'Generates diffs with removed download URLs'
+  task :bundled_dependencies, [:version] do |_, arguments|
+    run_on_source arguments[:version] do |third_party|
+      c_make_lists = third_party + 'CMakeLists.txt'
+      next unless c_make_lists.exist?
+
+      contents = c_make_lists.read
+      set_hhvm_start = contents.index 'SET_HHVM_THIRD_PARTY_SOURCE_ARGS('
+      next if set_hhvm_start.nil?
+
+      line = contents[..set_hhvm_start].count "\n"
+      in_lines = contents.lines
+      4.times { in_lines.delete_at(line + 2) }
+
+      puts Open3.capture2('diff', '-Nur', c_make_lists.to_path, '-', stdin_data: in_lines.join).first
+    end
+  end
+
+  desc 'Generated SlackBuild code to prepare bundled dependencies'
+  task :bundled_code, [:version] do |_, arguments|
+    run_on_source arguments[:version] do |third_party|
+      c_make_lists = third_party + 'CMakeLists.txt'
+      next unless c_make_lists.exist?
+
+      contents = c_make_lists.read
+      set_hhvm_start = contents.index 'SET_HHVM_THIRD_PARTY_SOURCE_ARGS('
+      next if set_hhvm_start.nil?
+
+      set_hhvm_end = contents.index ')', set_hhvm_start
+      set_hhvm_start += 'SET_HHVM_THIRD_PARTY_SOURCE_ARGS('.length
+      set_hhvm_end -= 1
+      contents = contents[set_hhvm_start..set_hhvm_end].split[1..].map(&:strip)
+
+      src = Pathname.new('third-party') +
+        third_party.basename +
+        "bundled_#{third_party.basename}-prefix" + 'src'
+      bundled = src + "bundled_#{third_party.basename}"
+      archive_name = contents[1][contents[1].rindex('/') + 1..-2]
+
+      puts "mkdir -p #{bundled}"
+      puts "install -m 0644 -D $CWD/#{archive_name} #{src + archive_name}"
+      puts "tar -zxvf $CWD/#{archive_name} -C #{bundled}"
+      puts
+    end
+  end
+end
+
+private
+
+def run_on_source(version, &block)
+  package = Package.new 'development/hhvm',
+    version: version,
+    homepage: 'https://hhvm.com/',
+    requires: %w[tbb glog libdwarf libmemcached dobule-conversion]
+  repository = SlackBuilder.clone 'https://github.com/facebook/hhvm.git', package, 'HHVM-'
+
+  (repository + 'third-party').each_child do |third_party|
+    block.call third_party
+  end
+end