diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index 5dc711ffdeec45..9b905db1f9aee6 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -496,7 +496,15 @@ def most_specific_locked_platform
     private :sources
 
     def nothing_changed?
-      !@source_changes && !@dependency_changes && !@new_platform && !@path_changes && !@local_changes && !@missing_lockfile_dep && !@unlocking_bundler && !@invalid_lockfile_dep
+      !@source_changes &&
+        !@dependency_changes &&
+        !@new_platform &&
+        !@path_changes &&
+        !@local_changes &&
+        !@missing_lockfile_dep &&
+        !@unlocking_bundler &&
+        !@locked_spec_with_missing_deps &&
+        !@locked_spec_with_invalid_deps
     end
 
     def no_resolve_needed?
@@ -653,7 +661,8 @@ def change_reason
         [@local_changes, "the gemspecs for git local gems changed"],
         [@missing_lockfile_dep, "your lock file is missing \"#{@missing_lockfile_dep}\""],
         [@unlocking_bundler, "an update to the version of Bundler itself was requested"],
-        [@invalid_lockfile_dep, "your lock file has an invalid dependency \"#{@invalid_lockfile_dep}\""],
+        [@locked_spec_with_missing_deps, "your lock file includes \"#{@locked_spec_with_missing_deps}\" but not some of its dependencies"],
+        [@locked_spec_with_invalid_deps, "your lockfile does not satisfy dependencies of \"#{@locked_spec_with_invalid_deps}\""],
       ].select(&:first).map(&:last).join(", ")
     end
 
@@ -708,26 +717,25 @@ def converge_locals
     end
 
     def check_lockfile
-      @invalid_lockfile_dep = nil
       @missing_lockfile_dep = nil
 
-      locked_names = @locked_specs.map(&:name)
+      @locked_spec_with_invalid_deps = nil
+      @locked_spec_with_missing_deps = nil
+
       missing = []
       invalid = []
 
       @locked_specs.each do |s|
-        s.dependencies.each do |dep|
-          next if dep.name == "bundler"
+        validation = @locked_specs.validate_deps(s)
 
-          missing << s unless locked_names.include?(dep.name)
-          invalid << s if @locked_specs.none? {|spec| dep.matches_spec?(spec) }
-        end
+        missing << s if validation == :missing
+        invalid << s if validation == :invalid
       end
 
       if missing.any?
         @locked_specs.delete(missing)
 
-        @missing_lockfile_dep = missing.first.name
+        @locked_spec_with_missing_deps = missing.first.name
       elsif !@dependency_changes
         @missing_lockfile_dep = current_dependencies.find do |d|
           @locked_specs[d.name].empty? && d.name != "bundler"
@@ -737,7 +745,7 @@ def check_lockfile
       if invalid.any?
         @locked_specs.delete(invalid)
 
-        @invalid_lockfile_dep = invalid.first.name
+        @locked_spec_with_invalid_deps = invalid.first.name
       end
     end
 
diff --git a/lib/bundler/lazy_specification.rb b/lib/bundler/lazy_specification.rb
index f2d10167325e58..38aea2a4aa83eb 100644
--- a/lib/bundler/lazy_specification.rb
+++ b/lib/bundler/lazy_specification.rb
@@ -10,6 +10,8 @@ class LazySpecification
     attr_reader :name, :version, :platform
     attr_accessor :source, :remote, :force_ruby_platform, :dependencies, :required_ruby_version, :required_rubygems_version
 
+    alias_method :runtime_dependencies, :dependencies
+
     def self.from_spec(s)
       lazy_spec = new(s.name, s.version, s.platform, s.source)
       lazy_spec.dependencies = s.dependencies
diff --git a/lib/bundler/remote_specification.rb b/lib/bundler/remote_specification.rb
index f626a3218e0503..9d237f3fa04834 100644
--- a/lib/bundler/remote_specification.rb
+++ b/lib/bundler/remote_specification.rb
@@ -88,6 +88,10 @@ def dependencies
       end
     end
 
+    def runtime_dependencies
+      dependencies.select(&:runtime?)
+    end
+
     def git_version
       return unless loaded_from && source.is_a?(Bundler::Source::Git)
       " #{source.revision[0..6]}"
diff --git a/lib/bundler/self_manager.rb b/lib/bundler/self_manager.rb
index 1925a266d977db..5accda4bcbaccc 100644
--- a/lib/bundler/self_manager.rb
+++ b/lib/bundler/self_manager.rb
@@ -121,7 +121,7 @@ def remote_specs
         source = Bundler::Source::Rubygems.new("remotes" => "https://rubygems.org")
         source.remote!
         source.add_dependency_names("bundler")
-        source.specs
+        source.specs.select(&:matches_current_metadata?)
       end
     end
 
diff --git a/lib/bundler/spec_set.rb b/lib/bundler/spec_set.rb
index a0ef3c2cb5871a..ceaac2cec523d0 100644
--- a/lib/bundler/spec_set.rb
+++ b/lib/bundler/spec_set.rb
@@ -37,7 +37,7 @@ def for(dependencies, check = false, platforms = [nil])
 
           specs_for_dep.first.dependencies.each do |d|
             next if d.type == :development
-            incomplete = true if d.name != "bundler" && lookup[d.name].empty?
+            incomplete = true if d.name != "bundler" && lookup[d.name].nil?
             deps << [d, dep[1]]
           end
         else
@@ -45,7 +45,7 @@ def for(dependencies, check = false, platforms = [nil])
         end
 
         if incomplete && check
-          @incomplete_specs += lookup[name].any? ? lookup[name] : [LazySpecification.new(name, nil, nil)]
+          @incomplete_specs += lookup[name] || [LazySpecification.new(name, nil, nil)]
         end
       end
 
@@ -64,7 +64,9 @@ def complete_platforms!(platforms)
         valid_platform = lookup.all? do |_, specs|
           spec = specs.first
           matching_specs = spec.source.specs.search([spec.name, spec.version])
-          platform_spec = GemHelpers.select_best_platform_match(matching_specs, platform).find(&:matches_current_metadata?)
+          platform_spec = GemHelpers.select_best_platform_match(matching_specs, platform).find do |s|
+            s.matches_current_metadata? && valid_dependencies?(s)
+          end
 
           if platform_spec
             new_specs << LazySpecification.from_spec(platform_spec)
@@ -90,9 +92,20 @@ def complete_platforms!(platforms)
       platforms
     end
 
+    def validate_deps(s)
+      s.runtime_dependencies.each do |dep|
+        next if dep.name == "bundler"
+
+        return :missing unless names.include?(dep.name)
+        return :invalid if none? {|spec| dep.matches_spec?(spec) }
+      end
+
+      :valid
+    end
+
     def [](key)
       key = key.name if key.respond_to?(:name)
-      lookup[key].reverse
+      lookup[key]&.reverse || []
     end
 
     def []=(key, value)
@@ -167,7 +180,7 @@ def delete_by_name(name)
     end
 
     def what_required(spec)
-      unless req = find {|s| s.dependencies.any? {|d| d.type == :runtime && d.name == spec.name } }
+      unless req = find {|s| s.runtime_dependencies.any? {|d| d.name == spec.name } }
         return [spec]
       end
       what_required(req) << spec
@@ -193,8 +206,16 @@ def each(&b)
       sorted.each(&b)
     end
 
+    def names
+      lookup.keys
+    end
+
     private
 
+    def valid_dependencies?(s)
+      validate_deps(s) == :valid
+    end
+
     def sorted
       rake = @specs.find {|s| s.name == "rake" }
       begin
@@ -213,8 +234,9 @@ def extract_circular_gems(error)
 
     def lookup
       @lookup ||= begin
-        lookup = Hash.new {|h, k| h[k] = [] }
+        lookup = {}
         @specs.each do |s|
+          lookup[s.name] ||= []
           lookup[s.name] << s
         end
         lookup
@@ -228,6 +250,8 @@ def tsort_each_node
 
     def specs_for_dependency(dep, platform)
       specs_for_name = lookup[dep.name]
+      return [] unless specs_for_name
+
       matching_specs = if dep.force_ruby_platform
         GemHelpers.force_ruby_platform(specs_for_name)
       else
@@ -240,7 +264,11 @@ def specs_for_dependency(dep, platform)
     def tsort_each_child(s)
       s.dependencies.sort_by(&:name).each do |d|
         next if d.type == :development
-        lookup[d.name].each {|s2| yield s2 }
+
+        specs_for_name = lookup[d.name]
+        next unless specs_for_name
+
+        specs_for_name.each {|s2| yield s2 }
       end
     end
   end
diff --git a/lib/bundler/vendor/thor/lib/thor/shell/color.rb b/lib/bundler/vendor/thor/lib/thor/shell/color.rb
index 6a9176331c34f1..5d708fadcad2dd 100644
--- a/lib/bundler/vendor/thor/lib/thor/shell/color.rb
+++ b/lib/bundler/vendor/thor/lib/thor/shell/color.rb
@@ -1,5 +1,4 @@
 require_relative "basic"
-require_relative "lcs_diff"
 
 class Bundler::Thor
   module Shell
@@ -7,8 +6,6 @@ module Shell
     # Bundler::Thor::Shell::Basic to see all available methods.
     #
     class Color < Basic
-      include LCSDiff
-
       # Embed in a String to clear all previous ANSI sequences.
       CLEAR      = "\e[0m"
       # The start of an ANSI bold sequence.
diff --git a/lib/bundler/vendor/thor/lib/thor/shell/html.rb b/lib/bundler/vendor/thor/lib/thor/shell/html.rb
index 6091485acbf726..0277b882b7ad99 100644
--- a/lib/bundler/vendor/thor/lib/thor/shell/html.rb
+++ b/lib/bundler/vendor/thor/lib/thor/shell/html.rb
@@ -1,5 +1,4 @@
 require_relative "basic"
-require_relative "lcs_diff"
 
 class Bundler::Thor
   module Shell
@@ -7,8 +6,6 @@ module Shell
     # Bundler::Thor::Shell::Basic to see all available methods.
     #
     class HTML < Basic
-      include LCSDiff
-
       # The start of an HTML bold sequence.
       BOLD       = "font-weight: bold"
 
diff --git a/lib/bundler/vendor/thor/lib/thor/shell/lcs_diff.rb b/lib/bundler/vendor/thor/lib/thor/shell/lcs_diff.rb
deleted file mode 100644
index 81268a9f028bd6..00000000000000
--- a/lib/bundler/vendor/thor/lib/thor/shell/lcs_diff.rb
+++ /dev/null
@@ -1,49 +0,0 @@
-module LCSDiff
-protected
-
-  # Overwrite show_diff to show diff with colors if Diff::LCS is
-  # available.
-  def show_diff(destination, content) #:nodoc:
-    if diff_lcs_loaded? && ENV["THOR_DIFF"].nil? && ENV["RAILS_DIFF"].nil?
-      actual  = File.binread(destination).to_s.split("\n")
-      content = content.to_s.split("\n")
-
-      Diff::LCS.sdiff(actual, content).each do |diff|
-        output_diff_line(diff)
-      end
-    else
-      super
-    end
-  end
-
-private
-
-  def output_diff_line(diff) #:nodoc:
-    case diff.action
-    when "-"
-      say "- #{diff.old_element.chomp}", :red, true
-    when "+"
-      say "+ #{diff.new_element.chomp}", :green, true
-    when "!"
-      say "- #{diff.old_element.chomp}", :red, true
-      say "+ #{diff.new_element.chomp}", :green, true
-    else
-      say "  #{diff.old_element.chomp}", nil, true
-    end
-  end
-
-  # Check if Diff::LCS is loaded. If it is, use it to create pretty output
-  # for diff.
-  def diff_lcs_loaded? #:nodoc:
-    return true if defined?(Diff::LCS)
-    return @diff_lcs_loaded unless @diff_lcs_loaded.nil?
-
-    @diff_lcs_loaded = begin
-      require "diff/lcs"
-      true
-    rescue LoadError
-      false
-    end
-  end
-
-end
diff --git a/lib/bundler/version.rb b/lib/bundler/version.rb
index 46a984283d6aed..a98d7fab30d7f7 100644
--- a/lib/bundler/version.rb
+++ b/lib/bundler/version.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 
 module Bundler
-  VERSION = "2.5.1".freeze
+  VERSION = "2.5.2".freeze
 
   def self.bundler_major_version
     @bundler_major_version ||= VERSION.split(".").first.to_i
diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index a5091b07b80465..fd5683f1be0cff 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -9,7 +9,7 @@
 require "rbconfig"
 
 module Gem
-  VERSION = "3.5.1"
+  VERSION = "3.5.2"
 end
 
 # Must be first since it unloads the prelude from 1.9.2
@@ -942,6 +942,13 @@ def self.suffixes
                    end].compact.uniq
   end
 
+  ##
+  # Suffixes for dynamic library require-able paths.
+
+  def self.dynamic_library_suffixes
+    @dynamic_library_suffixes ||= suffixes - [".rb"]
+  end
+
   ##
   # Prints the amount of time the supplied block takes to run using the debug
   # UI output.
diff --git a/lib/rubygems/basic_specification.rb b/lib/rubygems/basic_specification.rb
index cb6931b9747044..0380fceecefd62 100644
--- a/lib/rubygems/basic_specification.rb
+++ b/lib/rubygems/basic_specification.rb
@@ -84,7 +84,13 @@ def contains_requirable_file?(file)
       return false
     end
 
-    have_file? file, Gem.suffixes
+    is_soext = file.end_with?(".so", ".o")
+
+    if is_soext
+      have_file? file.delete_suffix(File.extname(file)), Gem.dynamic_library_suffixes
+    else
+      have_file? file, Gem.suffixes
+    end
   end
 
   def default_gem?
diff --git a/lib/rubygems/package.rb b/lib/rubygems/package.rb
index f3c1cb2895d516..387e40ffd753bb 100644
--- a/lib/rubygems/package.rb
+++ b/lib/rubygems/package.rb
@@ -268,7 +268,7 @@ def add_files(tar) # :nodoc:
 
       tar.add_file_simple file, stat.mode, stat.size do |dst_io|
         File.open file, "rb" do |src_io|
-          dst_io.write src_io.read 16_384 until src_io.eof?
+          copy_stream(src_io, dst_io)
         end
       end
     end
@@ -453,7 +453,7 @@ def extract_tar_gz(io, destination_dir, pattern = "*") # :nodoc:
         end
 
         if entry.file?
-          File.open(destination, "wb") {|out| out.write entry.read }
+          File.open(destination, "wb") {|out| copy_stream(entry, out) }
           FileUtils.chmod file_mode(entry.header.mode), destination
         end
 
@@ -714,6 +714,16 @@ def verify_gz(entry) # :nodoc:
   rescue Zlib::GzipFile::Error => e
     raise Gem::Package::FormatError.new(e.message, entry.full_name)
   end
+
+  if RUBY_ENGINE == "truffleruby"
+    def copy_stream(src, dst) # :nodoc:
+      dst.write src.read
+    end
+  else
+    def copy_stream(src, dst) # :nodoc:
+      IO.copy_stream(src, dst)
+    end
+  end
 end
 
 require_relative "package/digest_io"
diff --git a/lib/rubygems/request.rb b/lib/rubygems/request.rb
index dec0c35c633132..8702e223d67104 100644
--- a/lib/rubygems/request.rb
+++ b/lib/rubygems/request.rb
@@ -30,7 +30,7 @@ def initialize(uri, request_class, last_modified, pool)
     @uri = uri
     @request_class = request_class
     @last_modified = last_modified
-    @requests = Hash.new 0
+    @requests = Hash.new(0).compare_by_identity
     @user_agent = user_agent
 
     @connection_pool = pool
@@ -196,7 +196,7 @@ def perform_request(request) # :nodoc:
     bad_response = false
 
     begin
-      @requests[connection.object_id] += 1
+      @requests[connection] += 1
 
       verbose "#{request.method} #{Gem::Uri.redact(@uri)}"
 
@@ -247,7 +247,7 @@ def perform_request(request) # :nodoc:
     rescue EOFError, Gem::Timeout::Error,
            Errno::ECONNABORTED, Errno::ECONNRESET, Errno::EPIPE
 
-      requests = @requests[connection.object_id]
+      requests = @requests[connection]
       verbose "connection reset after #{requests} requests, retrying"
 
       raise Gem::RemoteFetcher::FetchError.new("too many connection resets", @uri) if retried
@@ -267,7 +267,7 @@ def perform_request(request) # :nodoc:
   # Resets HTTP connection +connection+.
 
   def reset(connection)
-    @requests.delete connection.object_id
+    @requests.delete connection
 
     connection.finish
     connection.start
diff --git a/spec/bundler/bundler/definition_spec.rb b/spec/bundler/bundler/definition_spec.rb
index 2e3c1584b13058..a19cf789ee9bb6 100644
--- a/spec/bundler/bundler/definition_spec.rb
+++ b/spec/bundler/bundler/definition_spec.rb
@@ -121,10 +121,7 @@
         gem "foo", :path => "#{lib_path("foo")}"
       G
 
-      bundle :check, env: { "DEBUG" => "1" }
-
-      expect(out).to match(/using resolution from the lockfile/)
-      expect(lockfile).to eq <<~G
+      expected_lockfile = <<~G
         PATH
           remote: #{lib_path("foo")}
           specs:
@@ -145,6 +142,13 @@
         BUNDLED WITH
            #{Bundler::VERSION}
       G
+
+      expect(lockfile).to eq(expected_lockfile)
+
+      bundle :check, env: { "DEBUG" => "1" }
+
+      expect(out).to match(/using resolution from the lockfile/)
+      expect(lockfile).to eq(expected_lockfile)
     end
 
     it "for a locked gem for another platform" do
diff --git a/spec/bundler/commands/update_spec.rb b/spec/bundler/commands/update_spec.rb
index 013cadd5413d71..59e7c3867c7e87 100644
--- a/spec/bundler/commands/update_spec.rb
+++ b/spec/bundler/commands/update_spec.rb
@@ -1371,26 +1371,28 @@
     expect(the_bundle).to include_gem "rack 1.0"
   end
 
-  it "updates the bundler version in the lockfile even if the latest version is not installed", :ruby_repo, :realworld do
+  it "updates the bundler version in the lockfile even if the latest version is not installed", :ruby_repo do
     pristine_system_gems "bundler-2.3.9"
 
     build_repo4 do
       build_gem "rack", "1.0"
+
+      build_bundler "999.0.0"
     end
 
-    install_gemfile <<-G, env: { "BUNDLER_IGNORE_DEFAULT_GEM" => "true" }
+    install_gemfile <<-G
       source "#{file_uri_for(gem_repo4)}"
       gem "rack"
     G
     lockfile lockfile.sub(/(^\s*)#{Bundler::VERSION}($)/, "2.3.9")
 
-    bundle :update, bundler: true, artifice: "vcr", verbose: true, env: { "BUNDLER_IGNORE_DEFAULT_GEM" => "true" }
+    bundle :update, bundler: true, artifice: "compact_index", verbose: true, env: { "BUNDLER_SPEC_GEM_REPO" => gem_repo4.to_s }
 
     # Only updates properly on modern RubyGems.
 
     if Gem.rubygems_version >= Gem::Version.new("3.3.0.dev")
-      expect(out).to include("Updating bundler to 2.3.10")
-      expect(out).to include("Using bundler 2.3.10")
+      expect(out).to include("Updating bundler to 999.0.0")
+      expect(out).to include("Using bundler 999.0.0")
       expect(out).not_to include("Installing Bundler 2.3.9 and restarting using that version.")
 
       expect(lockfile).to eq <<~L
@@ -1406,16 +1408,63 @@
           rack
 
         BUNDLED WITH
-           2.3.10
+           999.0.0
       L
 
-      expect(the_bundle).to include_gems "bundler 2.3.10"
+      expect(the_bundle).to include_gems "bundler 999.0.0"
+      expect(the_bundle).to include_gems "rack 1.0"
+    else
+      # Old RubyGems versions do not trampoline but they still change BUNDLED
+      # WITH to the latest bundler version. This means the below check fails
+      # because it tries to use bundler 999.0.0 which did not get installed.
+      # Workaround the bug by forcing the version we know is installed.
+      expect(the_bundle).to include_gems "rack 1.0", env: { "BUNDLER_VERSION" => "2.3.9" }
+    end
+  end
+
+  it "does not update the bundler version in the lockfile if the latest version is not compatible with current ruby", :ruby_repo do
+    pristine_system_gems "bundler-2.3.9"
+
+    build_repo4 do
+      build_gem "rack", "1.0"
+
+      build_bundler "2.3.9"
+      build_bundler "999.0.0" do |s|
+        s.required_ruby_version = "> #{Gem.ruby_version}"
+      end
     end
 
+    install_gemfile <<-G, env: { "BUNDLER_IGNORE_DEFAULT_GEM" => "true" }
+      source "#{file_uri_for(gem_repo4)}"
+      gem "rack"
+    G
+    lockfile lockfile.sub(/(^\s*)#{Bundler::VERSION}($)/, "2.3.9")
+
+    bundle :update, bundler: true, artifice: "compact_index", verbose: true, env: { "BUNDLER_SPEC_GEM_REPO" => gem_repo4.to_s, "BUNDLER_IGNORE_DEFAULT_GEM" => "true" }
+
+    expect(out).to include("Using bundler 2.3.9")
+
+    expect(lockfile).to eq <<~L
+      GEM
+        remote: #{file_uri_for(gem_repo4)}/
+        specs:
+          rack (1.0)
+
+      PLATFORMS
+        #{lockfile_platforms}
+
+      DEPENDENCIES
+        rack
+
+      BUNDLED WITH
+         2.3.9
+    L
+
+    expect(the_bundle).to include_gems "bundler 2.3.9"
     expect(the_bundle).to include_gems "rack 1.0"
   end
 
-  it "errors if the explicit target version does not exist", :realworld do
+  it "errors if the explicit target version does not exist" do
     pristine_system_gems "bundler-2.3.9"
 
     build_repo4 do
@@ -1428,7 +1477,7 @@
     G
     lockfile lockfile.sub(/(^\s*)#{Bundler::VERSION}($)/, "2.3.9")
 
-    bundle :update, bundler: "999.999.999", artifice: "vcr", raise_on_error: false
+    bundle :update, bundler: "999.999.999", artifice: "compact_index", raise_on_error: false
 
     # Only gives a meaningful error message on modern RubyGems.
 
diff --git a/spec/bundler/install/gemfile/specific_platform_spec.rb b/spec/bundler/install/gemfile/specific_platform_spec.rb
index 8b37570793908f..834465041123a4 100644
--- a/spec/bundler/install/gemfile/specific_platform_spec.rb
+++ b/spec/bundler/install/gemfile/specific_platform_spec.rb
@@ -1220,6 +1220,48 @@
     end
   end
 
+  it "does not add ruby platform gem if it brings extra dependencies not resolved originally" do
+    build_repo4 do
+      build_gem "nokogiri", "1.15.5" do |s|
+        s.add_dependency "mini_portile2", "~> 2.8.2"
+      end
+
+      build_gem "nokogiri", "1.15.5" do |s|
+        s.platform = "x86_64-linux"
+      end
+    end
+
+    gemfile <<~G
+      source "#{file_uri_for(gem_repo4)}"
+
+      gem "nokogiri"
+    G
+
+    checksums = checksums_section_when_existing do |c|
+      c.checksum gem_repo4, "nokogiri", "1.15.5", "x86_64-linux"
+    end
+
+    simulate_platform "x86_64-linux" do
+      bundle "install --verbose", artifice: "compact_index", env: { "BUNDLER_SPEC_GEM_REPO" => gem_repo4.to_s }
+
+      expect(lockfile).to eq(<<~L)
+        GEM
+          remote: #{file_uri_for(gem_repo4)}/
+          specs:
+            nokogiri (1.15.5-x86_64-linux)
+
+        PLATFORMS
+          x86_64-linux
+
+        DEPENDENCIES
+          nokogiri
+        #{checksums}
+        BUNDLED WITH
+           #{Bundler::VERSION}
+      L
+    end
+  end
+
   private
 
   def setup_multiplatform_gem
diff --git a/spec/bundler/lock/lockfile_spec.rb b/spec/bundler/lock/lockfile_spec.rb
index 8fe2f37054493a..5e996f5aaca02a 100644
--- a/spec/bundler/lock/lockfile_spec.rb
+++ b/spec/bundler/lock/lockfile_spec.rb
@@ -1603,7 +1603,7 @@
     L
 
     bundle "install --verbose"
-    expect(out).to include("re-resolving dependencies because your lock file is missing \"minitest-bisect\"")
+    expect(out).to include("re-resolving dependencies because your lock file includes \"minitest-bisect\" but not some of its dependencies")
 
     expect(lockfile).to eq <<~L
       GEM
diff --git a/spec/bundler/realworld/edgecases_spec.rb b/spec/bundler/realworld/edgecases_spec.rb
index c9af686dbe4123..dc70271b6e6b98 100644
--- a/spec/bundler/realworld/edgecases_spec.rb
+++ b/spec/bundler/realworld/edgecases_spec.rb
@@ -219,140 +219,6 @@ def rubygems_version(name, requirement)
     expect(err).to include("resque-scheduler 2.2.0 includes a gemspec with `require_paths` set to an array of arrays. Newer versions of this gem might've already fixed this").once
   end
 
-  it "doesn't hang on big gemfile" do
-    skip "Only for ruby 2.7" unless RUBY_VERSION.start_with?("2.7")
-
-    gemfile <<~G
-      # frozen_string_literal: true
-
-      source "https://rubygems.org"
-
-      ruby "~> 2.7.7"
-
-      gem "rails"
-      gem "pg", ">= 0.18", "< 2.0"
-      gem "goldiloader"
-      gem "awesome_nested_set"
-      gem "circuitbox"
-      gem "passenger"
-      gem "globalid"
-      gem "rack-cors"
-      gem "rails-pg-extras"
-      gem "linear_regression_trend"
-      gem "rack-protection"
-      gem "pundit"
-      gem "remote_ip_proxy_scrubber"
-      gem "bcrypt"
-      gem "searchkick"
-      gem "excon"
-      gem "faraday_middleware-aws-sigv4"
-      gem "typhoeus"
-      gem "sidekiq"
-      gem "sidekiq-undertaker"
-      gem "sidekiq-cron"
-      gem "storext"
-      gem "appsignal"
-      gem "fcm"
-      gem "business_time"
-      gem "tzinfo"
-      gem "holidays"
-      gem "bigdecimal"
-      gem "progress_bar"
-      gem "redis"
-      gem "hiredis"
-      gem "state_machines"
-      gem "state_machines-audit_trail"
-      gem "state_machines-activerecord"
-      gem "interactor"
-      gem "ar_transaction_changes"
-      gem "redis-rails"
-      gem "seed_migration"
-      gem "lograge"
-      gem "graphiql-rails", group: :development
-      gem "graphql"
-      gem "pusher"
-      gem "rbnacl"
-      gem "jwt"
-      gem "json-schema"
-      gem "discard"
-      gem "money"
-      gem "strip_attributes"
-      gem "validates_email_format_of"
-      gem "audited"
-      gem "concurrent-ruby"
-      gem "with_advisory_lock"
-
-      group :test do
-        gem "rspec-sidekiq"
-        gem "simplecov", require: false
-      end
-
-      group :development, :test do
-        gem "byebug", platform: :mri
-        gem "guard"
-        gem "guard-bundler"
-        gem "guard-rspec"
-        gem "rb-fsevent"
-        gem "rspec_junit_formatter"
-        gem "rspec-collection_matchers"
-        gem "rspec-rails"
-        gem "rspec-retry"
-        gem "state_machines-rspec"
-        gem "dotenv-rails"
-        gem "database_cleaner-active_record"
-        gem "database_cleaner-redis"
-        gem "timecop"
-      end
-
-      gem "factory_bot_rails"
-      gem "faker"
-
-      group :development do
-        gem "listen"
-        gem "sql_queries_count"
-        gem "rubocop"
-        gem "rubocop-performance"
-        gem "rubocop-rspec"
-        gem "rubocop-rails"
-        gem "brakeman"
-        gem "bundler-audit"
-        gem "solargraph"
-        gem "annotate"
-      end
-    G
-
-    if Bundler.feature_flag.bundler_3_mode?
-      # Conflicts on bundler version, so we count attempts differently
-      bundle :lock, env: { "DEBUG_RESOLVER" => "1" }, raise_on_error: false
-      expect(out.split("\n").grep(/backtracking to/).count).to eq(8)
-    else
-      bundle :lock, env: { "DEBUG_RESOLVER" => "1" }
-      expect(out).to include("Solution found after 7 attempts")
-    end
-  end
-
-  it "doesn't hang on tricky gemfile" do
-    skip "Only for ruby 2.7" unless RUBY_VERSION.start_with?("2.7")
-
-    gemfile <<~G
-      source 'https://rubygems.org'
-
-      group :development do
-        gem "puppet-module-posix-default-r2.7", '~> 0.3'
-        gem "puppet-module-posix-dev-r2.7", '~> 0.3'
-        gem "beaker-rspec"
-        gem "beaker-puppet"
-        gem "beaker-docker"
-        gem "beaker-puppet_install_helper"
-        gem "beaker-module_install_helper"
-      end
-    G
-
-    bundle :lock, env: { "DEBUG_RESOLVER" => "1" }
-
-    expect(out).to include("Solution found after 6 attempts")
-  end
-
   it "doesn't hang on nix gemfile" do
     skip "Only for ruby 3.0" unless RUBY_VERSION.start_with?("3.0")
 
diff --git a/spec/bundler/realworld/slow_perf_spec.rb b/spec/bundler/realworld/slow_perf_spec.rb
index d5ca51975aa904..be557d39027a56 100644
--- a/spec/bundler/realworld/slow_perf_spec.rb
+++ b/spec/bundler/realworld/slow_perf_spec.rb
@@ -30,4 +30,107 @@
 
     expect { bundle "lock" }.to take_less_than(30) # seconds
   end
+
+  it "resolves big gemfile quickly" do
+    gemfile <<~G
+      # frozen_string_literal: true
+
+      source "https://rubygems.org"
+
+      gem "rails"
+      gem "pg", ">= 0.18", "< 2.0"
+      gem "goldiloader"
+      gem "awesome_nested_set"
+      gem "circuitbox"
+      gem "passenger"
+      gem "globalid"
+      gem "rack-cors"
+      gem "rails-pg-extras"
+      gem "linear_regression_trend"
+      gem "rack-protection"
+      gem "pundit"
+      gem "remote_ip_proxy_scrubber"
+      gem "bcrypt"
+      gem "searchkick"
+      gem "excon"
+      gem "faraday_middleware-aws-sigv4"
+      gem "typhoeus"
+      gem "sidekiq"
+      gem "sidekiq-undertaker"
+      gem "sidekiq-cron"
+      gem "storext"
+      gem "appsignal"
+      gem "fcm"
+      gem "business_time"
+      gem "tzinfo"
+      gem "holidays"
+      gem "bigdecimal"
+      gem "progress_bar"
+      gem "redis"
+      gem "hiredis"
+      gem "state_machines"
+      gem "state_machines-audit_trail"
+      gem "state_machines-activerecord"
+      gem "interactor"
+      gem "ar_transaction_changes"
+      gem "redis-rails"
+      gem "seed_migration"
+      gem "lograge"
+      gem "graphiql-rails", group: :development
+      gem "graphql"
+      gem "pusher"
+      gem "rbnacl"
+      gem "jwt"
+      gem "json-schema"
+      gem "discard"
+      gem "money"
+      gem "strip_attributes"
+      gem "validates_email_format_of"
+      gem "audited"
+      gem "concurrent-ruby"
+      gem "with_advisory_lock"
+
+      group :test do
+        gem "rspec-sidekiq"
+        gem "simplecov", require: false
+      end
+
+      group :development, :test do
+        gem "byebug", platform: :mri
+        gem "guard"
+        gem "guard-bundler"
+        gem "guard-rspec"
+        gem "rb-fsevent"
+        gem "rspec_junit_formatter"
+        gem "rspec-collection_matchers"
+        gem "rspec-rails"
+        gem "rspec-retry"
+        gem "state_machines-rspec"
+        gem "dotenv-rails"
+        gem "database_cleaner-active_record"
+        gem "database_cleaner-redis"
+        gem "timecop"
+      end
+
+      gem "factory_bot_rails"
+      gem "faker"
+
+      group :development do
+        gem "listen"
+        gem "sql_queries_count"
+        gem "rubocop"
+        gem "rubocop-performance"
+        gem "rubocop-rspec"
+        gem "rubocop-rails"
+        gem "brakeman"
+        gem "bundler-audit"
+        gem "solargraph"
+        gem "annotate"
+      end
+    G
+
+    expect do
+      bundle "lock", env: { "DEBUG_RESOLVER" => "1" }, raise_on_error: !Bundler.feature_flag.bundler_3_mode?
+    end.to take_less_than(30) # seconds
+  end
 end
diff --git a/spec/bundler/support/artifice/helpers/compact_index.rb b/spec/bundler/support/artifice/helpers/compact_index.rb
index 8e7acb41a90442..cf8bb34c5afeae 100644
--- a/spec/bundler/support/artifice/helpers/compact_index.rb
+++ b/spec/bundler/support/artifice/helpers/compact_index.rb
@@ -77,7 +77,7 @@ def gems(gem_repo = default_gem_repo)
 
         specs.group_by(&:name).map do |name, versions|
           gem_versions = versions.map do |spec|
-            deps = spec.dependencies.select {|d| d.type == :runtime }.map do |d|
+            deps = spec.runtime_dependencies.map do |d|
               reqs = d.requirement.requirements.map {|r| r.join(" ") }.join(", ")
               CompactIndex::Dependency.new(d.name, reqs)
             end
diff --git a/spec/bundler/support/artifice/helpers/endpoint.rb b/spec/bundler/support/artifice/helpers/endpoint.rb
index 6115e91535f5ff..be52df69365ff3 100644
--- a/spec/bundler/support/artifice/helpers/endpoint.rb
+++ b/spec/bundler/support/artifice/helpers/endpoint.rb
@@ -72,7 +72,7 @@ def dependencies_for(gem_names, gem_repo = default_gem_repo)
           name: spec.name,
           number: spec.version.version,
           platform: spec.platform.to_s,
-          dependencies: spec.dependencies.select {|dep| dep.type == :runtime }.map do |dep|
+          dependencies: spec.runtime_dependencies.map do |dep|
             [dep.name, dep.requirement.requirements.map {|a| a.join(" ") }.join(", ")]
           end,
         }
diff --git a/spec/bundler/support/builders.rb b/spec/bundler/support/builders.rb
index 1763e091fe2c81..68e3bd7c7b60fa 100644
--- a/spec/bundler/support/builders.rb
+++ b/spec/bundler/support/builders.rb
@@ -297,6 +297,10 @@ def build_lib(name, *args, &blk)
       build_with(LibBuilder, name, args, &blk)
     end
 
+    def build_bundler(*args, &blk)
+      build_with(BundlerBuilder, "bundler", args, &blk)
+    end
+
     def build_gem(name, *args, &blk)
       build_with(GemBuilder, name, args, &blk)
     end
@@ -402,6 +406,49 @@ def required_ruby_version=(*reqs)
       alias_method :dep, :runtime
     end
 
+    class BundlerBuilder
+      attr_writer :required_ruby_version
+
+      def initialize(context, name, version)
+        raise "can only build bundler" unless name == "bundler"
+
+        @context = context
+        @version = version || Bundler::VERSION
+      end
+
+      def _build(options = {})
+        full_name = "bundler-#{@version}"
+        build_path = @context.tmp + full_name
+        bundler_path = build_path + "#{full_name}.gem"
+
+        Dir.mkdir build_path
+
+        @context.shipped_files.each do |shipped_file|
+          target_shipped_file = shipped_file
+          target_shipped_file = shipped_file.sub(/\Alibexec/, "exe") if @context.ruby_core?
+          target_shipped_file = build_path + target_shipped_file
+          target_shipped_dir = File.dirname(target_shipped_file)
+          FileUtils.mkdir_p target_shipped_dir unless File.directory?(target_shipped_dir)
+          FileUtils.cp shipped_file, target_shipped_file, preserve: true
+        end
+
+        @context.replace_version_file(@version, dir: build_path)
+        @context.replace_required_ruby_version(@required_ruby_version, dir: build_path) if @required_ruby_version
+
+        Spec::BuildMetadata.write_build_metadata(dir: build_path)
+
+        @context.gem_command "build #{@context.relative_gemspec}", dir: build_path
+
+        if block_given?
+          yield(bundler_path)
+        else
+          FileUtils.mv bundler_path, options[:path]
+        end
+      ensure
+        build_path.rmtree
+      end
+    end
+
     class LibBuilder
       def initialize(context, name, version)
         @context = context
diff --git a/spec/bundler/support/helpers.rb b/spec/bundler/support/helpers.rb
index 5e5a6a6e3b6d21..64ed0553b84d59 100644
--- a/spec/bundler/support/helpers.rb
+++ b/spec/bundler/support/helpers.rb
@@ -326,34 +326,8 @@ def install_gem(path, install_dir, default = false)
       gem_command "install #{args} '#{path}'"
     end
 
-    def with_built_bundler(version = nil)
-      version ||= Bundler::VERSION
-      full_name = "bundler-#{version}"
-      build_path = tmp + full_name
-      bundler_path = build_path + "#{full_name}.gem"
-
-      Dir.mkdir build_path
-
-      begin
-        shipped_files.each do |shipped_file|
-          target_shipped_file = shipped_file
-          target_shipped_file = shipped_file.sub(/\Alibexec/, "exe") if ruby_core?
-          target_shipped_file = build_path + target_shipped_file
-          target_shipped_dir = File.dirname(target_shipped_file)
-          FileUtils.mkdir_p target_shipped_dir unless File.directory?(target_shipped_dir)
-          FileUtils.cp shipped_file, target_shipped_file, preserve: true
-        end
-
-        replace_version_file(version, dir: build_path)
-
-        Spec::BuildMetadata.write_build_metadata(dir: build_path)
-
-        gem_command "build #{relative_gemspec}", dir: build_path
-
-        yield(bundler_path)
-      ensure
-        build_path.rmtree
-      end
+    def with_built_bundler(version = nil, &block)
+      Builders::BundlerBuilder.new(self, "bundler", version)._build(&block)
     end
 
     def with_gem_path_as(path)
diff --git a/spec/bundler/support/matchers.rb b/spec/bundler/support/matchers.rb
index ea7c784683517e..9d604bec25500c 100644
--- a/spec/bundler/support/matchers.rb
+++ b/spec/bundler/support/matchers.rb
@@ -103,7 +103,21 @@ def self.define_compound_matcher(matcher, preconditions, &declarations)
 
         actual.call
 
-        (Time.now - start_time).to_f < seconds
+        actual_time = (Time.now - start_time).to_f
+
+        acceptable = actual_time < seconds
+
+        @errors = ["took #{actual_time} seconds"] unless acceptable
+
+        acceptable
+      end
+
+      failure_message do
+        super() + " but:\n" + @errors.map {|e| indent(e) }.join("\n")
+      end
+
+      failure_message_when_negated do
+        super() + " but:\n" + @errors.map {|e| indent(e) }.join("\n")
       end
 
       supports_block_expectations
diff --git a/spec/bundler/support/path.rb b/spec/bundler/support/path.rb
index 3dbc553c0148e1..7352d5a35316ef 100644
--- a/spec/bundler/support/path.rb
+++ b/spec/bundler/support/path.rb
@@ -250,6 +250,13 @@ def replace_version_file(version, dir: source_root)
       File.open(version_file, "w") {|f| f << contents }
     end
 
+    def replace_required_ruby_version(version, dir:)
+      gemspec_file = File.expand_path("bundler.gemspec", dir)
+      contents = File.read(gemspec_file)
+      contents.sub!(/(^\s+s\.required_ruby_version\s*=\s*)"[^"]+"/, %(\\1"#{version}"))
+      File.open(gemspec_file, "w") {|f| f << contents }
+    end
+
     def ruby_core?
       # avoid to warnings
       @ruby_core ||= nil
diff --git a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock
index e1d83f092d207d..0937f71973f5f8 100644
--- a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock
+++ b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock
@@ -152,18 +152,18 @@ dependencies = [
 
 [[package]]
 name = "rb-sys"
-version = "0.9.83"
+version = "0.9.84"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e5b8d560b60790a3e60e56e73a8c7be88ac14e6af39fc82b5eca72c71753840"
+checksum = "3def04a96a36ef8681a2b2e26c01683b93a8630175c845fa06cab76c5a8c7ce0"
 dependencies = [
  "rb-sys-build",
 ]
 
 [[package]]
 name = "rb-sys-build"
-version = "0.9.83"
+version = "0.9.84"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2d2bfd00002007d7e9ad93d0397437933040caf452d260c26dbef5fd95ae1a6"
+checksum = "c017d134afd764dd43c2faa91aa50b698a3bb4ff30e83113da483c789e74be8c"
 dependencies = [
  "bindgen",
  "lazy_static",
diff --git a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml
index 7596823e08caa4..68834952827e21 100644
--- a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml
+++ b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml
@@ -7,4 +7,4 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-rb-sys = "0.9.83"
+rb-sys = "0.9.84"
diff --git a/test/rubygems/test_gem_specification.rb b/test/rubygems/test_gem_specification.rb
index 5601f286a95b40..5f0546b93da9e9 100644
--- a/test/rubygems/test_gem_specification.rb
+++ b/test/rubygems/test_gem_specification.rb
@@ -1561,6 +1561,17 @@ def test_contains_requirable_file_eh_extension_java_platform
     assert_empty err
   end
 
+  def test_contains_requirable_file_extension_soext
+    ext_spec
+    dlext = RbConfig::CONFIG["DLEXT"]
+    @ext.files += ["lib/ext.#{dlext}"]
+
+    FileUtils.mkdir_p @ext.extension_dir
+    FileUtils.touch File.join(@ext.extension_dir, "ext.#{dlext}")
+    FileUtils.touch File.join(@ext.extension_dir, "gem.build_complete")
+    assert @ext.contains_requirable_file? "ext.so"
+  end
+
   def test_date
     assert_date @a1.date
   end