Support no_build_extension and no_install_plugin settings in Bundler

Extend the --no-build-extension and --no-install-plugin support to
Bundler's installation paths. RubyGemsGemInstaller#install now
respects these options, and the settings are propagated from
Bundler::Settings through Source::RubyGems to the installer.

Path::Installer also respects no_build_extension for git/path sources.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hsbt

bundler/lib/bundler/rubygems_gem_installer.rb

@@ -27,15 +27,19 @@ def install
         extract_files
       end
 
-      build_extensions if spec.extensions.any?
+      if options[:build_extension] == false
+        warn_skipped_extensions
+      elsif spec.extensions.any?
+        build_extensions
+      end
       write_build_info_file
       run_post_build_hooks
 
       SharedHelpers.filesystem_access(bin_dir, :write) do
         generate_bin
       end
 
-      generate_plugins
+      generate_plugins unless options[:install_plugin] == false
 
       write_spec
 

bundler/lib/bundler/settings.rb

@@ -30,7 +30,9 @@ class Settings
       init_gems_rb
       inline
       lockfile_checksums
+      no_build_extension
       no_install
+      no_install_plugin
       no_prune
       path.system
       plugins

bundler/lib/bundler/source/path/installer.rb

@@ -24,7 +24,7 @@ def initialize(spec, options = {})
         def post_install
           run_hooks(:pre_install)
 
-          unless @disable_extensions
+          unless @disable_extensions || Bundler.settings[:no_build_extension]
             build_extensions
             run_hooks(:post_build)
           end

bundler/lib/bundler/source/rubygems.rb

@@ -533,7 +533,9 @@ def rubygems_gem_installer(spec, options)
             wrappers: true,
             env_shebang: true,
             build_args: options[:build_args],
-            bundler_extension_cache_path: extension_cache_path(spec)
+            bundler_extension_cache_path: extension_cache_path(spec),
+            build_extension: Bundler.settings[:no_build_extension] ? false : nil,
+            install_plugin: Bundler.settings[:no_install_plugin] ? false : nil
           )
           @gem_installers_mutex.synchronize { @gem_installers[spec.name] ||= installer }
         end

spec/install/gems/no_build_extension_spec.rb

@@ -0,0 +1,52 @@
+# frozen_string_literal: true
+
+RSpec.describe "bundle install with --no-build-extension" do
+  before do
+    build_repo2 do
+      build_gem "with_extension" do |s|
+        s.extensions << "Rakefile"
+        s.write "Rakefile", <<-RUBY
+          task :default do
+            path = File.expand_path("lib", __dir__)
+            FileUtils.mkdir_p(path)
+            File.open("\#{path}/with_extension.rb", "w") do |f|
+              f.puts "WITH_EXTENSION = 'YES'"
+            end
+          end
+        RUBY
+      end
+    end
+  end
+
+  it "skips building native extensions when no_build_extension is set" do
+    bundle_config "no_build_extension true"
+
+    gemfile <<-G
+      source "https://gem.repo2"
+      gem "with_extension"
+      gem "rake"
+    G
+
+    bundle :install
+
+    build_complete = default_bundle_path("extensions").join(
+      Gem::Platform.local.to_s,
+      Gem.extension_api_version.to_s,
+      "with_extension-1.0",
+      "gem.build_complete"
+    )
+    expect(build_complete).not_to exist
+  end
+
+  it "builds native extensions by default" do
+    gemfile <<-G
+      source "https://gem.repo2"
+      gem "with_extension"
+      gem "rake"
+    G
+
+    bundle :install
+
+    expect(out).to include("Installing with_extension 1.0 with native extensions")
+  end
+end