Update bundled bundler to 1.16.0.

  * lib/bundler, spec/bundler: Merge bundler-1.16.0.
  * common.mk: rspec examples of bundler-1.16.0 needs require option.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60603 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

8 files changed, 269 insertions, 121 deletions

diff --git a/lib/bundler/source/gemspec.rb b/lib/bundler/source/gemspec.rb
index 05e613277f..7e3447e776 100644
--- a/lib/bundler/source/gemspec.rb
+++ b/lib/bundler/source/gemspec.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module Bundler
   class Source
     class Gemspec < Path
diff --git a/lib/bundler/source/git.rb b/lib/bundler/source/git.rb
index b3e218e390..a1a59ddce5 100644
--- a/lib/bundler/source/git.rb
+++ b/lib/bundler/source/git.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
-require "fileutils"
+
+require "bundler/vendored_fileutils"
 require "uri"
-require "digest/sha1"
 
 module Bundler
   class Source
@@ -18,7 +18,7 @@ module Bundler
         @allow_remote = false
 
         # Stringify options that could be set as symbols
-        %w(ref branch tag revision).each {|k| options[k] = options[k].to_s if options[k] }
+        %w[ref branch tag revision].each {|k| options[k] = options[k].to_s if options[k] }
 
         @uri        = options["uri"] || ""
         @branch     = options["branch"]
@@ -39,7 +39,7 @@ module Bundler
         out = String.new("GIT\n")
         out << "  remote: #{@uri}\n"
         out << "  revision: #{revision}\n"
-        %w(ref branch tag submodules).each do |opt|
+        %w[ref branch tag submodules].each do |opt|
           out << "  #{opt}: #{options[opt]}\n" if options[opt]
         end
         out << "  glob: #{@glob}\n" unless @glob == DEFAULT_GLOB
@@ -169,15 +169,13 @@ module Bundler
       def install(spec, options = {})
         force = options[:force]
 
-        Bundler.ui.info "Using #{version_message(spec)} from #{self}"
+        print_using_message "Using #{version_message(spec)} from #{self}"
 
-        if requires_checkout? && !@copied && !force
+        if (requires_checkout? && !@copied) || force
           Bundler.ui.debug "  * Checking out revision: #{ref}"
           git_proxy.copy_to(install_path, submodules)
           serialize_gemspecs_in(install_path)
           @copied = true
-        elsif force
-          git_proxy.copy_to(install_path, submodules)
         end
 
         generate_bin_options = { :disable_extensions => !Bundler.rubygems.spec_missing_extensions?(spec), :build_args => options[:build_args] }
@@ -188,7 +186,7 @@ module Bundler
 
       def cache(spec, custom_path = nil)
         app_cache_path = app_cache_path(custom_path)
-        return unless Bundler.settings[:cache_all]
+        return unless Bundler.feature_flag.cache_all?
         return if path == app_cache_path
         cached!
         FileUtils.rm_rf(app_cache_path)
@@ -210,13 +208,11 @@ module Bundler
       # When using local git repos, this is set to the local repo.
       def cache_path
         @cache_path ||= begin
-          git_scope = "#{base_name}-#{uri_hash}"
-
-          if Bundler.requires_sudo?
-            Bundler.user_bundle_path.join("cache/git", git_scope)
+          if Bundler.requires_sudo? || Bundler.feature_flag.global_gem_cache?
+            Bundler.user_cache
           else
-            Bundler.cache.join("git", git_scope)
-          end
+            Bundler.bundle_path.join("cache", "bundler")
+          end.join("git", git_scope)
         end
       end
 
@@ -287,7 +283,7 @@ module Bundler
           # If there is no URI scheme, assume it is an ssh/git URI
           input = uri
         end
-        Digest::SHA1.hexdigest(input)
+        SharedHelpers.digest(:SHA1).hexdigest(input)
       end
 
       def cached_revision
@@ -304,9 +300,9 @@ module Bundler
 
       def fetch
         git_proxy.checkout
-      rescue GitError
+      rescue GitError => e
         raise unless Bundler.feature_flag.allow_offline_install?
-        Bundler.ui.warn "Using cached git data because of network errors"
+        Bundler.ui.warn "Using cached git data because of network errors:\n#{e}"
       end
 
       # no-op, since we validate when re-serializing the gemspec
@@ -319,6 +315,14 @@ module Bundler
           StubSpecification.from_stub(stub)
         end
       end
+
+      def git_scope
+        "#{base_name}-#{uri_hash}"
+      end
+
+      def extension_cache_slug(_)
+        extension_dir_name
+      end
     end
   end
 end
diff --git a/lib/bundler/source/git/git_proxy.rb b/lib/bundler/source/git/git_proxy.rb
index c05d7a5afa..c56dda66ea 100644
--- a/lib/bundler/source/git/git_proxy.rb
+++ b/lib/bundler/source/git/git_proxy.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require "shellwords"
 require "tempfile"
 module Bundler
@@ -62,7 +63,7 @@ module Bundler
           begin
             @revision ||= find_local_revision
           rescue GitCommandError
-            raise MissingGitRevisionError.new(ref, uri)
+            raise MissingGitRevisionError.new(ref, URICredentialsFilter.credential_filtered_uri(uri))
           end
 
           @revision
@@ -90,18 +91,21 @@ module Bundler
         end
 
         def checkout
-          if path.exist?
-            return if has_revision_cached?
-            Bundler.ui.info "Fetching #{URICredentialsFilter.credential_filtered_uri(uri)}"
-            in_path do
-              git_retry %(fetch --force --quiet --tags #{uri_escaped_with_configured_credentials} "refs/heads/*:refs/heads/*")
-            end
-          else
-            Bundler.ui.info "Fetching #{URICredentialsFilter.credential_filtered_uri(uri)}"
+          return if path.exist? && has_revision_cached?
+          extra_ref = "#{Shellwords.shellescape(ref)}:#{Shellwords.shellescape(ref)}" if ref && ref.start_with?("refs/")
+
+          Bundler.ui.info "Fetching #{URICredentialsFilter.credential_filtered_uri(uri)}"
+
+          unless path.exist?
             SharedHelpers.filesystem_access(path.dirname) do |p|
               FileUtils.mkdir_p(p)
             end
             git_retry %(clone #{uri_escaped_with_configured_credentials} "#{path}" --bare --no-hardlinks --quiet)
+            return unless extra_ref
+          end
+
+          in_path do
+            git_retry %(fetch --force --quiet --tags #{uri_escaped_with_configured_credentials} "refs/heads/*:refs/heads/*" #{extra_ref})
           end
         end
 
@@ -149,7 +153,7 @@ module Bundler
         end
 
         def git_retry(command)
-          Bundler::Retry.new("`git #{command}`", GitNotAllowedError).attempts do
+          Bundler::Retry.new("`git #{URICredentialsFilter.credential_filtered_string(command, uri)}`", GitNotAllowedError).attempts do
             git(command)
           end
         end
@@ -217,6 +221,7 @@ module Bundler
 
         def in_path(&blk)
           checkout unless path.exist?
+          _ = URICredentialsFilter # load it before we chdir
           SharedHelpers.chdir(path, &blk)
         end
 
diff --git a/lib/bundler/source/metadata.rb b/lib/bundler/source/metadata.rb
new file mode 100644
index 0000000000..93909002c7
--- /dev/null
+++ b/lib/bundler/source/metadata.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+module Bundler
+  class Source
+    class Metadata < Source
+      def specs
+        @specs ||= Index.build do |idx|
+          idx << Gem::Specification.new("ruby\0", RubyVersion.system.to_gem_version_with_patchlevel)
+          idx << Gem::Specification.new("rubygems\0", Gem::VERSION)
+
+          idx << Gem::Specification.new do |s|
+            s.name     = "bundler"
+            s.version  = VERSION
+            s.platform = Gem::Platform::RUBY
+            s.source   = self
+            s.authors  = ["bundler team"]
+            s.bindir   = "exe"
+            s.executables = %w[bundle]
+            # can't point to the actual gemspec or else the require paths will be wrong
+            s.loaded_from = File.expand_path("..", __FILE__)
+          end
+          if loaded_spec = nil && Bundler.rubygems.loaded_specs("bundler")
+            idx << loaded_spec # this has to come after the fake gemspec, to override it
+          elsif local_spec = Bundler.rubygems.find_name("bundler").find {|s| s.version.to_s == VERSION }
+            idx << local_spec
+          end
+
+          idx.each {|s| s.source = self }
+        end
+      end
+
+      def cached!; end
+
+      def remote!; end
+
+      def options
+        {}
+      end
+
+      def install(spec, _opts = {})
+        print_using_message "Using #{version_message(spec)}"
+        nil
+      end
+
+      def to_s
+        "the local ruby installation"
+      end
+
+      def ==(other)
+        self.class == other.class
+      end
+      alias_method :eql?, :==
+
+      def hash
+        self.class.hash
+      end
+
+      def version_message(spec)
+        "#{spec.name} #{spec.version}"
+      end
+    end
+  end
+end
diff --git a/lib/bundler/source/path.rb b/lib/bundler/source/path.rb
index 8dd0763cc1..ed734bf549 100644
--- a/lib/bundler/source/path.rb
+++ b/lib/bundler/source/path.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module Bundler
   class Source
     class Path < Source
@@ -35,10 +36,12 @@ module Bundler
       end
 
       def remote!
+        @local_specs = nil
         @allow_remote = true
       end
 
       def cached!
+        @local_specs = nil
         @allow_cached = true
       end
 
@@ -74,14 +77,14 @@ module Bundler
       end
 
       def install(spec, options = {})
-        Bundler.ui.info "Using #{version_message(spec)} from #{self}"
+        print_using_message "Using #{version_message(spec)} from #{self}"
         generate_bin(spec, :disable_extensions => true)
         nil # no post-install message
       end
 
       def cache(spec, custom_path = nil)
         app_cache_path = app_cache_path(custom_path)
-        return unless Bundler.settings[:cache_all]
+        return unless Bundler.feature_flag.cache_all?
         return if expand(@original_path).to_s.index(root_path.to_s + "/") == 0
 
         unless @original_path.exist?
@@ -113,10 +116,6 @@ module Bundler
         Bundler.root
       end
 
-      def is_a_path?
-        instance_of?(Path)
-      end
-
       def expanded_original_path
         @expanded_original_path ||= expand(original_path)
       end
@@ -228,7 +227,8 @@ module Bundler
           spec,
           :env_shebang => false,
           :disable_extensions => options[:disable_extensions],
-          :build_args => options[:build_args]
+          :build_args => options[:build_args],
+          :bundler_extension_cache_path => extension_cache_path(spec)
         )
         installer.post_install
       rescue Gem::InvalidSpecificationException => e
@@ -242,7 +242,7 @@ module Bundler
                           "to modify their .gemspec so it can work with `gem build`."
         end
 
-        Bundler.ui.warn "The validation message from Rubygems was:\n  #{e.message}"
+        Bundler.ui.warn "The validation message from RubyGems was:\n  #{e.message}"
       end
     end
   end
diff --git a/lib/bundler/source/path/installer.rb b/lib/bundler/source/path/installer.rb
index 9c2f74a31b..a0357ffa39 100644
--- a/lib/bundler/source/path/installer.rb
+++ b/lib/bundler/source/path/installer.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module Bundler
   class Source
     class Path
@@ -6,6 +7,7 @@ module Bundler
         attr_reader :spec
 
         def initialize(spec, options = {})
+          @options            = options
           @spec               = spec
           @gem_dir            = Bundler.rubygems.path(spec.full_gem_path)
           @wrappers           = true
diff --git a/lib/bundler/source/rubygems.rb b/lib/bundler/source/rubygems.rb
index 353194f53f..6f4157364f 100644
--- a/lib/bundler/source/rubygems.rb
+++ b/lib/bundler/source/rubygems.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 require "uri"
 require "rubygems/user_interaction"
 
@@ -31,6 +32,7 @@ module Bundler
       end
 
       def cached!
+        @specs = nil
         @allow_cached = true
       end
 
@@ -49,6 +51,7 @@ module Bundler
       end
 
       def can_lock?(spec)
+        return super if Bundler.feature_flag.lockfile_uses_separate_rubygems_sources?
         spec.source.is_a?(Rubygems)
       end
 
@@ -69,8 +72,12 @@ module Bundler
       end
 
       def to_s
-        remote_names = remotes.map(&:to_s).join(", ")
-        "rubygems repository #{remote_names}"
+        if remotes.empty?
+          "locally installed gems"
+        else
+          remote_names = remotes.map(&:to_s).join(", ")
+          "rubygems repository #{remote_names} or installed locally"
+        end
       end
       alias_method :name, :to_s
 
@@ -99,8 +106,8 @@ module Bundler
           end
         end
 
-        if installed?(spec) && (!force || spec.name.eql?("bundler"))
-          Bundler.ui.info "Using #{version_message(spec)}"
+        if installed?(spec) && !force
+          print_using_message "Using #{version_message(spec)}"
           return nil # no post-install message
         end
 
@@ -141,7 +148,8 @@ module Bundler
               :wrappers            => true,
               :env_shebang         => true,
               :build_args          => opts[:build_args],
-              :bundler_expected_checksum => spec.respond_to?(:checksum) && spec.checksum
+              :bundler_expected_checksum => spec.respond_to?(:checksum) && spec.checksum,
+              :bundler_extension_cache_path => extension_cache_path(spec)
             ).install
           end
           spec.full_gem_path = installed_spec.full_gem_path
@@ -212,13 +220,21 @@ module Bundler
         @remotes.unshift(uri) unless @remotes.include?(uri)
       end
 
-      def replace_remotes(other_remotes)
+      def equivalent_remotes?(other_remotes)
+        other_remotes.map(&method(:remove_auth)) == @remotes.map(&method(:remove_auth))
+      end
+
+      def replace_remotes(other_remotes, allow_equivalent = false)
         return false if other_remotes == @remotes
 
+        equivalent = allow_equivalent && equivalent_remotes?(other_remotes)
+
         @remotes = []
         other_remotes.reverse_each do |r|
           add_remote r.to_s
         end
+
+        !equivalent
       end
 
       def unmet_deps
@@ -236,6 +252,43 @@ module Bundler
         end
       end
 
+      def double_check_for(unmet_dependency_names, override_dupes = false, index = specs)
+        return unless @allow_remote
+        raise ArgumentError, "missing index" unless index
+
+        return unless api_fetchers.any?
+
+        unmet_dependency_names = unmet_dependency_names.call
+        unless unmet_dependency_names.nil?
+          if api_fetchers.size <= 1
+            # can't do this when there are multiple fetchers because then we might not fetch from _all_
+            # of them
+            unmet_dependency_names -= remote_specs.spec_names # avoid re-fetching things we've already gotten
+          end
+          return if unmet_dependency_names.empty?
+        end
+
+        Bundler.ui.debug "Double checking for #{unmet_dependency_names || "all specs (due to the size of the request)"} in #{self}"
+
+        fetch_names(api_fetchers, unmet_dependency_names, index, override_dupes)
+      end
+
+      def dependency_names_to_double_check
+        names = []
+        remote_specs.each do |spec|
+          case spec
+          when EndpointSpecification, Gem::Specification, StubSpecification, LazySpecification
+            names.concat(spec.runtime_dependencies)
+          when RemoteSpecification # from the full index
+            return nil
+          else
+            raise "unhandled spec type (#{spec.inspect})"
+          end
+        end
+        names.map!(&:name) if names
+        names
+      end
+
     protected
 
       def credless_remotes
@@ -276,7 +329,7 @@ module Bundler
       end
 
       def suppress_configured_credentials(remote)
-        remote_nouser = remote.dup.tap {|uri| uri.user = uri.password = nil }.to_s
+        remote_nouser = remove_auth(remote)
         if remote.userinfo && remote.userinfo == Bundler.settings[remote_nouser]
           remote_nouser
         else
@@ -284,15 +337,14 @@ module Bundler
         end
       end
 
+      def remove_auth(remote)
+        remote.dup.tap {|uri| uri.user = uri.password = nil }.to_s
+      end
+
       def installed_specs
-        @installed_specs ||= begin
-          idx = Index.new
-          have_bundler = false
+        @installed_specs ||= Index.build do |idx|
           Bundler.rubygems.all_specs.reverse_each do |spec|
-            if spec.name == "bundler"
-              next unless spec.version.to_s == VERSION
-              have_bundler = true
-            end
+            next if spec.name == "bundler"
             spec.source = self
             if Bundler.rubygems.spec_missing_extensions?(spec, false)
               Bundler.ui.debug "Source #{self} is ignoring #{spec} because it is missing extensions"
@@ -300,23 +352,6 @@ module Bundler
             end
             idx << spec
           end
-
-          # Always have bundler locally
-          unless have_bundler
-            # We're running bundler directly from the source
-            # so, let's create a fake gemspec for it (it's a path)
-            # gemspec
-            bundler = Gem::Specification.new do |s|
-              s.name     = "bundler"
-              s.version  = VERSION
-              s.platform = Gem::Platform::RUBY
-              s.source   = self
-              s.authors  = ["bundler team"]
-              s.loaded_from = File.expand_path("..", __FILE__)
-            end
-            idx << bundler
-          end
-          idx
         end
       end
 
@@ -334,9 +369,9 @@ module Bundler
             end
             idx << s
           end
-        end
 
-        idx
+          idx
+        end
       end
 
       def api_fetchers
@@ -348,71 +383,36 @@ module Bundler
           index_fetchers = fetchers - api_fetchers
 
           # gather lists from non-api sites
-          index_fetchers.each do |f|
-            Bundler.ui.info "Fetching source index from #{f.uri}"
-            idx.use f.specs_with_retry(nil, self)
-          end
+          fetch_names(index_fetchers, nil, idx, false)
 
           # because ensuring we have all the gems we need involves downloading
           # the gemspecs of those gems, if the non-api sites contain more than
-          # about 100 gems, we treat all sites as non-api for speed.
+          # about 500 gems, we treat all sites as non-api for speed.
           allow_api = idx.size < API_REQUEST_LIMIT && dependency_names.size < API_REQUEST_LIMIT
           Bundler.ui.debug "Need to query more than #{API_REQUEST_LIMIT} gems." \
             " Downloading full index instead..." unless allow_api
 
-          if allow_api
-            api_fetchers.each do |f|
-              Bundler.ui.info "Fetching gem metadata from #{f.uri}", Bundler.ui.debug?
-              idx.use f.specs_with_retry(dependency_names, self)
-              Bundler.ui.info "" unless Bundler.ui.debug? # new line now that the dots are over
-            end
-
-            # Suppose the gem Foo depends on the gem Bar.  Foo exists in Source A.  Bar has some versions that exist in both
-            # sources A and B.  At this point, the API request will have found all the versions of Bar in source A,
-            # but will not have found any versions of Bar from source B, which is a problem if the requested version
-            # of Foo specifically depends on a version of Bar that is only found in source B. This ensures that for
-            # each spec we found, we add all possible versions from all sources to the index.
-            loop do
-              idxcount = idx.size
-              api_fetchers.each do |f|
-                Bundler.ui.info "Fetching version metadata from #{f.uri}", Bundler.ui.debug?
-                idx.use f.specs_with_retry(idx.dependency_names, self), true
-                Bundler.ui.info "" unless Bundler.ui.debug? # new line now that the dots are over
-              end
-              break if idxcount == idx.size
-            end
-
-            if api_fetchers.any?
-              # it's possible that gems from one source depend on gems from some
-              # other source, so now we download gemspecs and iterate over those
-              # dependencies, looking for gems we don't have info on yet.
-              unmet = idx.unmet_dependency_names
-
-              # if there are any cross-site gems we missed, get them now
-              api_fetchers.each do |f|
-                Bundler.ui.info "Fetching dependency metadata from #{f.uri}", Bundler.ui.debug?
-                idx.use f.specs_with_retry(unmet, self)
-                Bundler.ui.info "" unless Bundler.ui.debug? # new line now that the dots are over
-              end if unmet.any?
-            else
-              allow_api = false
-            end
-          end
+          fetch_names(api_fetchers, allow_api && dependency_names, idx, false)
+        end
+      end
 
-          unless allow_api
-            api_fetchers.each do |f|
-              Bundler.ui.info "Fetching source index from #{f.uri}"
-              idx.use f.specs_with_retry(nil, self)
-            end
+      def fetch_names(fetchers, dependency_names, index, override_dupes)
+        fetchers.each do |f|
+          if dependency_names
+            Bundler.ui.info "Fetching gem metadata from #{f.uri}", Bundler.ui.debug?
+            index.use f.specs_with_retry(dependency_names, self), override_dupes
+            Bundler.ui.info "" unless Bundler.ui.debug? # new line now that the dots are over
+          else
+            Bundler.ui.info "Fetching source index from #{f.uri}"
+            index.use f.specs_with_retry(nil, self), override_dupes
           end
         end
       end
 
       def fetch_gem(spec)
         return false unless spec.remote
-        uri = spec.remote.uri
+
         spec.fetch_platform
-        Bundler.ui.confirm("Fetching #{version_message(spec)}")
 
         download_path = requires_sudo? ? Bundler.tmp(spec.full_name) : rubygems_dir
         gem_path = "#{rubygems_dir}/cache/#{spec.full_name}.gem"
@@ -420,7 +420,7 @@ module Bundler
         SharedHelpers.filesystem_access("#{download_path}/cache") do |p|
           FileUtils.mkdir_p(p)
         end
-        Bundler.rubygems.download_gem(spec, uri, download_path)
+        download_gem(spec, download_path)
 
         if requires_sudo?
           SharedHelpers.filesystem_access("#{rubygems_dir}/cache") do |p|
@@ -457,6 +457,76 @@ module Bundler
       def cache_path
         Bundler.app_cache
       end
+
+    private
+
+      # Checks if the requested spec exists in the global cache. If it does,
+      # we copy it to the download path, and if it does not, we download it.
+      #
+      # @param  [Specification] spec
+      #         the spec we want to download or retrieve from the cache.
+      #
+      # @param  [String] download_path
+      #         the local directory the .gem will end up in.
+      #
+      def download_gem(spec, download_path)
+        local_path = File.join(download_path, "cache/#{spec.full_name}.gem")
+
+        if (cache_path = download_cache_path(spec)) && cache_path.file?
+          SharedHelpers.filesystem_access(local_path) do
+            FileUtils.cp(cache_path, local_path)
+          end
+        else
+          uri = spec.remote.uri
+          Bundler.ui.confirm("Fetching #{version_message(spec)}")
+          Bundler.rubygems.download_gem(spec, uri, download_path)
+          cache_globally(spec, local_path)
+        end
+      end
+
+      # Checks if the requested spec exists in the global cache. If it does
+      # not, we create the relevant global cache subdirectory if it does not
+      # exist and copy the spec from the local cache to the global cache.
+      #
+      # @param  [Specification] spec
+      #         the spec we want to copy to the global cache.
+      #
+      # @param  [String] local_cache_path
+      #         the local directory from which we want to copy the .gem.
+      #
+      def cache_globally(spec, local_cache_path)
+        return unless cache_path = download_cache_path(spec)
+        return if cache_path.exist?
+
+        SharedHelpers.filesystem_access(cache_path.dirname, &:mkpath)
+        SharedHelpers.filesystem_access(cache_path) do
+          FileUtils.cp(local_cache_path, cache_path)
+        end
+      end
+
+      # Returns the global cache path of the calling Rubygems::Source object.
+      #
+      # Note that the Source determines the path's subdirectory. We use this
+      # subdirectory in the global cache path so that gems with the same name
+      # -- and possibly different versions -- from different sources are saved
+      # to their respective subdirectories and do not override one another.
+      #
+      # @param  [Gem::Specification] specification
+      #
+      # @return [Pathname] The global cache path.
+      #
+      def download_cache_path(spec)
+        return unless Bundler.feature_flag.global_gem_cache?
+        return unless remote = spec.remote
+        return unless cache_slug = remote.cache_slug
+
+        Bundler.user_cache.join("gems", cache_slug, spec.file_name)
+      end
+
+      def extension_cache_slug(spec)
+        return unless remote = spec.remote
+        remote.cache_slug
+      end
     end
   end
 end
diff --git a/lib/bundler/source/rubygems/remote.rb b/lib/bundler/source/rubygems/remote.rb
index b49e645506..e73baaa992 100644
--- a/lib/bundler/source/rubygems/remote.rb
+++ b/lib/bundler/source/rubygems/remote.rb
@@ -1,4 +1,5 @@
 # frozen_string_literal: true
+
 module Bundler
   class Source
     class Rubygems
@@ -20,10 +21,12 @@ module Bundler
         #
         def cache_slug
           @cache_slug ||= begin
+            return nil unless SharedHelpers.md5_available?
+
             cache_uri = original_uri || uri
 
             uri_parts = [cache_uri.host, cache_uri.user, cache_uri.port, cache_uri.path]
-            uri_digest = Digest::MD5.hexdigest(uri_parts.compact.join("."))
+            uri_digest = SharedHelpers.digest(:MD5).hexdigest(uri_parts.compact.join("."))
 
             uri_parts[-1] = uri_digest
             uri_parts.compact.join(".")