[Content Addressable] Add support for Packaging Single-ABI Gems

.github/actions/cibuildgem/action.yml

@@ -9,6 +9,10 @@ inputs:
   step:
     description: "The step to run"
     required: true
+  include-single-abi:
+    description: "Whether to also compile a set of single-ABI gems."
+    required: false
+    default: false
   test-command:
     description: "The command to run the test suite. By default cibuildgem will run either `bundle exec rake test` or `bundle exec rake spec` depending on the test framework used."
     required: false
@@ -48,7 +52,7 @@ runs:
       if: "${{ inputs.step == 'compile' }}"
       working-directory: ${{ inputs.working-directory }}
       shell: bash
-      run: cibuildgem package
+      run: cibuildgem package --include-single-abi "${{ inputs.include-single-abi }}"
     - name: Upload artifacts
       if: "${{ inputs.step == 'compile' }}"
       uses: actions/upload-artifact@v4
@@ -66,6 +70,27 @@ runs:
       with:
         name: "stage-${{ runner.os }}-${{ runner.arch }}"
         path: "${{ inputs.working-directory }}"
+    - name: "Install single-ABI gem"
+      if: "${{ inputs.step == 'test_cross' && inputs.include-single-abi == 'true' }}"
+      working-directory: ${{ inputs.working-directory }}
+      shell: bash
+      run: |
+        ruby <<'RUBY' > /tmp/single-abi-gems
+        require "rubygems/package"
+
+        ruby_abi = RUBY_VERSION.split(".").first(2).join(".")
+        expected_requirement = Gem::Requirement.new("~> #{ruby_abi}.0")
+        gems = Dir["pkg/*.gem"].select do |path|
+          spec = Gem::Package.new(path).spec
+          spec.platform != Gem::Platform::RUBY && spec.required_ruby_version == expected_requirement
+        end
+
+        abort "No single-ABI gem found for Ruby #{ruby_abi}" if gems.empty?
+
+        puts gems
+        RUBY
+
+        xargs gem install < /tmp/single-abi-gems
     - name: "Copy staging binary to the libdir"
       if: "${{ inputs.step == 'test_cross' }}"
       working-directory: ${{ inputs.working-directory }}

.github/workflows/e2e-dummy-gem.yml

@@ -24,6 +24,7 @@ jobs:
         with:
           step: "compile"
           working-directory: "test/fixtures/dummy_gem"
+          include-single-abi: true
   test:
     timeout-minutes: 20
     name: "Run the test suite"
@@ -48,6 +49,7 @@ jobs:
         with:
           step: "test_${{ matrix.type }}"
           working-directory: "test/fixtures/dummy_gem"
+          include-single-abi: true
   install:
     timeout-minutes: 5
     name: "Verify the gem can be installed"

lib/cibuildgem/cli.rb

@@ -36,7 +36,7 @@ def compile
       run_rake_tasks!("cibuildgem:setup", :compile)
     end
 
-    desc "package", "Compile and package a 'fat gem'.", hide: true
+    desc "package", "Compile and package a 'multi-ABI gem'.", hide: true
     long_desc <<~MSG
       This command should normally run on CI, using the cibuildgem workflow. It will not work locally unless
       the environment is properly setup.
@@ -46,13 +46,20 @@ def compile
       - A gem without precompiled binary (Ruby platform).
 
       The gem with precompiled binaries will be packaged with multiple binaries compatible for different
-      Ruby ABI (depending on what Ruby version the gem supports).
+      Ruby ABI (depending on what Ruby version the gem supports). If `--include-single-abi` is passed,
+      cibuildgem will also compile a set of single-ABI gems per Ruby version supported by the gem.
     MSG
     method_option "gemspec", type: "string", required: false, desc: "The gemspec to use. Defaults to the gemspec from the current working directory."
+    method_option "include-single-abi", type: :boolean, required: false, default: false, desc: "Whether to also compile a set of single-ABI gems. Defaults to false."
     def package
       ENV["RUBY_CC_VERSION"] ||= compilation_task.ruby_cc_version
-
-      run_rake_tasks!("cibuildgem:setup", :cross, :native, :gem)
+      run_rake_tasks!(
+        "cibuildgem:setup",
+        :cross,
+        :native,
+        :gem,
+        env: { CompilationTasks::CONTENT_ADDRESSABLE_ENV => options["include-single-abi"] == true ? "true" : "false" },
+      )
     end
 
     desc "test", "Run the test suites of the target gem"
@@ -158,7 +165,7 @@ def verify_releasable_filename!(pathname)
       MSG
     end
 
-    def run_rake_tasks!(*tasks)
+    def run_rake_tasks!(*tasks, env: {})
       rakelibdir = [File.expand_path("tasks", __dir__), "rakelib"].join(File::PATH_SEPARATOR)
       rake_compiler_path = Gem.loaded_specs["rake-compiler"].full_require_paths
       rake_specs = Gem.loaded_specs["rake"]
@@ -169,7 +176,7 @@ def run_rake_tasks!(*tasks)
       patch = File.expand_path("../extension_patch.rb", __FILE__)
 
       system(
-        { "RUBYLIB" => load_paths },
+        { "RUBYLIB" => load_paths }.merge(env),
         "bundle",
         "exec",
         RbConfig.ruby,

lib/cibuildgem/compilation_tasks.rb

@@ -7,13 +7,20 @@
 
 module Cibuildgem
   class CompilationTasks
-    attr_reader :gemspec, :native, :create_packaging_task, :extension_task
+    CONTENT_ADDRESSABLE_ENV = "CIBUILDGEM_CONTENT_ADDRESSABLE"
 
-    def initialize(create_packaging_task = false, gemspec = nil)
+    attr_reader :gemspec, :native, :create_packaging_task, :extension_task, :content_addressable
+
+    def initialize(
+      create_packaging_task = false,
+      gemspec = nil,
+      content_addressable: ENV[CONTENT_ADDRESSABLE_ENV] == "true"
+    )
       @gemspec = Bundler.load_gemspec(gemspec || find_gemspec)
       verify_gemspec!
 
       @create_packaging_task = create_packaging_task
+      @content_addressable = content_addressable
     end
 
     def setup
@@ -62,6 +69,14 @@ def define_task(path, binary_name)
       @extension_task.cross_platform = normalized_platform
       @extension_task.cross_compile = true
       @extension_task.no_native = true
+      if content_addressable
+        if @extension_task.respond_to?(:content_addressable=)
+          @extension_task.content_addressable = true
+        else
+          warn("WARNING: content-addressable packaging was requested, but rake-compiler does not support it. " \
+            "Upgrade rake-compiler to build single-ABI gems.")
+        end
+      end
 
       Rake::ExtensionTask.enable!
       @extension_task.define

test/cli_test.rb

@@ -7,6 +7,8 @@
 
 module Cibuildgem
   class CLITest < Minitest::Test
+    TEST_CONTENT_ADDRESSABLE_ENV = "CIBUILDGEM_CONTENT_ADDRESSABLE"
+
     def setup
       super
 
@@ -15,6 +17,7 @@ def setup
 
     def teardown
       ENV.delete("RUBY_CC_VERSION")
+      ENV.delete(TEST_CONTENT_ADDRESSABLE_ENV)
 
       super
     end
@@ -328,6 +331,116 @@ def test_package_when_a_rakefile_defines_an_extension_task
       assert_predicate($CHILD_STATUS, :success?)
     end
 
+    def test_package_single_abi_enables_content_addressable_packaging_for_one_rake_run
+      cli = CLI.new([], { "include-single-abi" => true })
+      compilation_task = Struct.new(:ruby_cc_version).new("3.3.8:3.2.8")
+      rake_calls = []
+      run_rake_tasks = proc do |*tasks, env: {}|
+        rake_calls << [
+          ENV.fetch("RUBY_CC_VERSION"),
+          env.fetch(TEST_CONTENT_ADDRESSABLE_ENV),
+          tasks,
+        ]
+      end
+
+      cli.stub(:compilation_task, compilation_task) do
+        cli.stub(:run_rake_tasks!, run_rake_tasks) do
+          cli.package
+        end
+      end
+
+      assert_equal(
+        [["3.3.8:3.2.8", "true", ["cibuildgem:setup", :cross, :native, :gem]]],
+        rake_calls,
+      )
+      assert_nil(ENV[TEST_CONTENT_ADDRESSABLE_ENV])
+    end
+
+    def test_package_defaults_to_multi_abi_and_preserves_ruby_cc_version_from_environment
+      ENV["RUBY_CC_VERSION"] = "3.1.6"
+      cli = CLI.new
+      compilation_task = Struct.new(:ruby_cc_version).new("3.3.8:3.2.8")
+      rake_calls = []
+      run_rake_tasks = proc do |*tasks, env: {}|
+        rake_calls << [
+          ENV.fetch("RUBY_CC_VERSION"),
+          env.fetch(TEST_CONTENT_ADDRESSABLE_ENV),
+          tasks,
+        ]
+      end
+
+      cli.stub(:compilation_task, compilation_task) do
+        cli.stub(:run_rake_tasks!, run_rake_tasks) do
+          cli.package
+        end
+      end
+
+      assert_equal(
+        [["3.1.6", "false", ["cibuildgem:setup", :cross, :native, :gem]]],
+        rake_calls,
+      )
+    end
+
+    def test_compilation_task_enables_content_addressable_extension_task
+      require "cibuildgem/extension_patch"
+
+      extension_task = Class.new do
+        attr_accessor :config_script,
+          :content_addressable,
+          :cross_compile,
+          :cross_platform,
+          :ext_dir,
+          :gem_spec,
+          :lib_dir,
+          :name,
+          :no_native
+
+        def define; end
+      end.new
+      original_current = Rake::ExtensionTask.current
+
+      Dir.chdir("test/fixtures/dummy_gem") do
+        Rake::ExtensionTask.current = extension_task
+        CompilationTasks.new(false, nil, content_addressable: true).setup
+      end
+
+      assert_equal(true, extension_task.content_addressable)
+    ensure
+      Rake::ExtensionTask.current = original_current if Rake::ExtensionTask.respond_to?(:current=)
+      Rake::Task.clear
+    end
+
+    def test_compilation_task_warns_when_rake_compiler_does_not_support_content_addressable
+      require "cibuildgem/extension_patch"
+
+      extension_task = Class.new do
+        attr_accessor :config_script,
+          :cross_compile,
+          :cross_platform,
+          :ext_dir,
+          :gem_spec,
+          :lib_dir,
+          :name,
+          :no_native
+
+        def define; end
+      end.new
+      original_current = Rake::ExtensionTask.current
+
+      _, err = capture_io do
+        Dir.chdir("test/fixtures/dummy_gem") do
+          Rake::ExtensionTask.current = extension_task
+          CompilationTasks.new(false, nil, content_addressable: true).setup
+        end
+      end
+
+      assert_includes(err, "content-addressable packaging was requested")
+      assert_includes(err, "Upgrade rake-compiler")
+    ensure
+      Rake::ExtensionTask.current = original_current if Rake::ExtensionTask.respond_to?(:current=)
+      Rake::Task.clear
+    end
+
     def test_keep_the_extension_task_config_defined_by_the_gem
       Dir.chdir("test/fixtures/with_configured_ext") do
         cli = CLI.new