Merge Bundler 2.1.0.pre.3

  Features:
    - Add caller information to some deprecation messages to make them easier to fix [#7361](https://github.com/bundler/bundler/pull/7361)
    - Reconcile `bundle cache` vs `bundle package` everywhere. Now in docs, CLI help and everywhere else `bundle cache` is the preferred version and `bundle package` remains as an alias [#7389](https://github.com/bundler/bundler/pull/7389)
    - Display some basic `bundler` documentation together with ruby's RDoc based documentation [#7394](https://github.com/bundler/bundler/pull/7394)

  Bugfixes:
    - Fix typos deprecation message and upgrading docs [#7374](https://github.com/bundler/bundler/pull/7374)
    - Deprecation warnings about `taint` usage on ruby 2.7 [#7385](https://github.com/bundler/bundler/pull/7385)
    - Fix `--help` flag not correctly delegating to `man` when used with command aliases [#7388](https://github.com/bundler/bundler/pull/7388)
    - `bundle add` should cache newly added gems if an application cache exists [#7393](https://github.com/bundler/bundler/pull/7393)
    - Stop using an insecure folder as a "fallback home" when user home is not defined [#7416](https://github.com/bundler/bundler/pull/7416)
    - Fix `bundler/inline` warning about `Bundler.root` redefinition [#7417](https://github.com/bundler/bundler/pull/7417)

49 files changed, 267 insertions, 105 deletions

diff --git a/spec/bundler/support/artifice/compact_index.rb b/spec/bundler/support/artifice/compact_index.rb
index 4f01690ae4..89362c4dbc 100644
--- a/spec/bundler/support/artifice/compact_index.rb
+++ b/spec/bundler/support/artifice/compact_index.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 $LOAD_PATH.unshift Dir[base_system_gems.join("gems/compact_index*/lib")].first.to_s
 require "compact_index"
diff --git a/spec/bundler/support/artifice/compact_index_api_missing.rb b/spec/bundler/support/artifice/compact_index_api_missing.rb
index 94e6b73000..fdd342bc08 100644
--- a/spec/bundler/support/artifice/compact_index_api_missing.rb
+++ b/spec/bundler/support/artifice/compact_index_api_missing.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_basic_authentication.rb b/spec/bundler/support/artifice/compact_index_basic_authentication.rb
index 97aa6cbd84..775f1a3977 100644
--- a/spec/bundler/support/artifice/compact_index_basic_authentication.rb
+++ b/spec/bundler/support/artifice/compact_index_basic_authentication.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_checksum_mismatch.rb b/spec/bundler/support/artifice/compact_index_checksum_mismatch.rb
index 62feb9f164..1abe64236c 100644
--- a/spec/bundler/support/artifice/compact_index_checksum_mismatch.rb
+++ b/spec/bundler/support/artifice/compact_index_checksum_mismatch.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_concurrent_download.rb b/spec/bundler/support/artifice/compact_index_concurrent_download.rb
index 972ecb88b7..7f989a3f37 100644
--- a/spec/bundler/support/artifice/compact_index_concurrent_download.rb
+++ b/spec/bundler/support/artifice/compact_index_concurrent_download.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_creds_diff_host.rb b/spec/bundler/support/artifice/compact_index_creds_diff_host.rb
index 0d349bcc1e..6c3442e14b 100644
--- a/spec/bundler/support/artifice/compact_index_creds_diff_host.rb
+++ b/spec/bundler/support/artifice/compact_index_creds_diff_host.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_extra.rb b/spec/bundler/support/artifice/compact_index_extra.rb
index 84d1859235..3a09afd06f 100644
--- a/spec/bundler/support/artifice/compact_index_extra.rb
+++ b/spec/bundler/support/artifice/compact_index_extra.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_extra_api.rb b/spec/bundler/support/artifice/compact_index_extra_api.rb
index 903aa900fb..3c716763c0 100644
--- a/spec/bundler/support/artifice/compact_index_extra_api.rb
+++ b/spec/bundler/support/artifice/compact_index_extra_api.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_extra_api_missing.rb b/spec/bundler/support/artifice/compact_index_extra_api_missing.rb
index e72040f604..6bd24ddbb4 100644
--- a/spec/bundler/support/artifice/compact_index_extra_api_missing.rb
+++ b/spec/bundler/support/artifice/compact_index_extra_api_missing.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index_extra_api", __FILE__)
+require_relative "compact_index_extra_api"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_extra_missing.rb b/spec/bundler/support/artifice/compact_index_extra_missing.rb
index 67a9d23691..4758b785ac 100644
--- a/spec/bundler/support/artifice/compact_index_extra_missing.rb
+++ b/spec/bundler/support/artifice/compact_index_extra_missing.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index_extra", __FILE__)
+require_relative "compact_index_extra"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_forbidden.rb b/spec/bundler/support/artifice/compact_index_forbidden.rb
index 0a4dfdb2e8..3eebe0fbd8 100644
--- a/spec/bundler/support/artifice/compact_index_forbidden.rb
+++ b/spec/bundler/support/artifice/compact_index_forbidden.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_host_redirect.rb b/spec/bundler/support/artifice/compact_index_host_redirect.rb
index ab371117de..304c897d68 100644
--- a/spec/bundler/support/artifice/compact_index_host_redirect.rb
+++ b/spec/bundler/support/artifice/compact_index_host_redirect.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_no_gem.rb b/spec/bundler/support/artifice/compact_index_no_gem.rb
index 01c5be1b3d..0a4be08a46 100644
--- a/spec/bundler/support/artifice/compact_index_no_gem.rb
+++ b/spec/bundler/support/artifice/compact_index_no_gem.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_partial_update.rb b/spec/bundler/support/artifice/compact_index_partial_update.rb
index eaedff5105..6e7c05d423 100644
--- a/spec/bundler/support/artifice/compact_index_partial_update.rb
+++ b/spec/bundler/support/artifice/compact_index_partial_update.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_range_not_satisfiable.rb b/spec/bundler/support/artifice/compact_index_range_not_satisfiable.rb
index 487be4771a..788f9d6f99 100644
--- a/spec/bundler/support/artifice/compact_index_range_not_satisfiable.rb
+++ b/spec/bundler/support/artifice/compact_index_range_not_satisfiable.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_rate_limited.rb b/spec/bundler/support/artifice/compact_index_rate_limited.rb
index d8f4fc941c..ba17476045 100644
--- a/spec/bundler/support/artifice/compact_index_rate_limited.rb
+++ b/spec/bundler/support/artifice/compact_index_rate_limited.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_redirects.rb b/spec/bundler/support/artifice/compact_index_redirects.rb
index e83451b5b6..99adc797bf 100644
--- a/spec/bundler/support/artifice/compact_index_redirects.rb
+++ b/spec/bundler/support/artifice/compact_index_redirects.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_strict_basic_authentication.rb b/spec/bundler/support/artifice/compact_index_strict_basic_authentication.rb
index abbf3258e7..7d427b5382 100644
--- a/spec/bundler/support/artifice/compact_index_strict_basic_authentication.rb
+++ b/spec/bundler/support/artifice/compact_index_strict_basic_authentication.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_wrong_dependencies.rb b/spec/bundler/support/artifice/compact_index_wrong_dependencies.rb
index 7e1d3686e2..036fac70b3 100644
--- a/spec/bundler/support/artifice/compact_index_wrong_dependencies.rb
+++ b/spec/bundler/support/artifice/compact_index_wrong_dependencies.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/compact_index_wrong_gem_checksum.rb b/spec/bundler/support/artifice/compact_index_wrong_gem_checksum.rb
index db4d8e3974..8add32b88f 100644
--- a/spec/bundler/support/artifice/compact_index_wrong_gem_checksum.rb
+++ b/spec/bundler/support/artifice/compact_index_wrong_gem_checksum.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../compact_index", __FILE__)
+require_relative "compact_index"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endopint_marshal_fail_basic_authentication.rb b/spec/bundler/support/artifice/endopint_marshal_fail_basic_authentication.rb
index 12a6fa153f..c341c3993f 100644
--- a/spec/bundler/support/artifice/endopint_marshal_fail_basic_authentication.rb
+++ b/spec/bundler/support/artifice/endopint_marshal_fail_basic_authentication.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint_marshal_fail", __FILE__)
+require_relative "endpoint_marshal_fail"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint.rb b/spec/bundler/support/artifice/endpoint.rb
index 966681f8d8..bf26c56503 100644
--- a/spec/bundler/support/artifice/endpoint.rb
+++ b/spec/bundler/support/artifice/endpoint.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require File.expand_path("../../path.rb", __FILE__)
-require Spec::Path.root.join("lib/bundler/deprecate")
+require_relative "../path"
+require Spec::Path.lib_dir.join("bundler/deprecate")
 include Spec::Path
 
 $LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gems.join("gems/{artifice,mustermann,rack,tilt,sinatra}-*/lib")].map(&:to_s))
@@ -44,7 +44,7 @@ class Endpoint < Sinatra::Base
     def dependencies_for(gem_names, gem_repo = GEM_REPO)
       return [] if gem_names.nil? || gem_names.empty?
 
-      require "#{Spec::Path.lib}/bundler"
+      require "#{Spec::Path.lib_dir}/bundler"
       Bundler::Deprecate.skip_during do
         all_specs = %w[specs.4.8 prerelease_specs.4.8].map do |filename|
           Marshal.load(File.open(gem_repo.join(filename)).read)
diff --git a/spec/bundler/support/artifice/endpoint_500.rb b/spec/bundler/support/artifice/endpoint_500.rb
index ad51d58e67..f98e7e3bc2 100644
--- a/spec/bundler/support/artifice/endpoint_500.rb
+++ b/spec/bundler/support/artifice/endpoint_500.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../../path.rb", __FILE__)
+require_relative "../path"
 include Spec::Path
 
 $LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gems.join("gems/{artifice,mustermann,rack,tilt,sinatra}-*/lib")].map(&:to_s))
diff --git a/spec/bundler/support/artifice/endpoint_api_forbidden.rb b/spec/bundler/support/artifice/endpoint_api_forbidden.rb
index bb89747adc..edc2463424 100644
--- a/spec/bundler/support/artifice/endpoint_api_forbidden.rb
+++ b/spec/bundler/support/artifice/endpoint_api_forbidden.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_api_missing.rb b/spec/bundler/support/artifice/endpoint_api_missing.rb
index 2ada0dc553..8dafde7362 100644
--- a/spec/bundler/support/artifice/endpoint_api_missing.rb
+++ b/spec/bundler/support/artifice/endpoint_api_missing.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_basic_authentication.rb b/spec/bundler/support/artifice/endpoint_basic_authentication.rb
index 223671bc29..ff3d1493d6 100644
--- a/spec/bundler/support/artifice/endpoint_basic_authentication.rb
+++ b/spec/bundler/support/artifice/endpoint_basic_authentication.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_creds_diff_host.rb b/spec/bundler/support/artifice/endpoint_creds_diff_host.rb
index 925954b12d..f20ef74ac6 100644
--- a/spec/bundler/support/artifice/endpoint_creds_diff_host.rb
+++ b/spec/bundler/support/artifice/endpoint_creds_diff_host.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_extra.rb b/spec/bundler/support/artifice/endpoint_extra.rb
index 422f65401b..31f6822161 100644
--- a/spec/bundler/support/artifice/endpoint_extra.rb
+++ b/spec/bundler/support/artifice/endpoint_extra.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_extra_api.rb b/spec/bundler/support/artifice/endpoint_extra_api.rb
index 62e2c2bb93..213b8e5895 100644
--- a/spec/bundler/support/artifice/endpoint_extra_api.rb
+++ b/spec/bundler/support/artifice/endpoint_extra_api.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_extra_missing.rb b/spec/bundler/support/artifice/endpoint_extra_missing.rb
index 038a12610a..ee129025ff 100644
--- a/spec/bundler/support/artifice/endpoint_extra_missing.rb
+++ b/spec/bundler/support/artifice/endpoint_extra_missing.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint_extra", __FILE__)
+require_relative "endpoint_extra"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_fallback.rb b/spec/bundler/support/artifice/endpoint_fallback.rb
index 554c08f0a2..08edf232e3 100644
--- a/spec/bundler/support/artifice/endpoint_fallback.rb
+++ b/spec/bundler/support/artifice/endpoint_fallback.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_host_redirect.rb b/spec/bundler/support/artifice/endpoint_host_redirect.rb
index cda5664be2..338cbcad00 100644
--- a/spec/bundler/support/artifice/endpoint_host_redirect.rb
+++ b/spec/bundler/support/artifice/endpoint_host_redirect.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_marshal_fail.rb b/spec/bundler/support/artifice/endpoint_marshal_fail.rb
index 2a5dcdc2fd..22c13e3e17 100644
--- a/spec/bundler/support/artifice/endpoint_marshal_fail.rb
+++ b/spec/bundler/support/artifice/endpoint_marshal_fail.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint_fallback", __FILE__)
+require_relative "endpoint_fallback"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_mirror_source.rb b/spec/bundler/support/artifice/endpoint_mirror_source.rb
index 64452f198d..318866e420 100644
--- a/spec/bundler/support/artifice/endpoint_mirror_source.rb
+++ b/spec/bundler/support/artifice/endpoint_mirror_source.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 class EndpointMirrorSource < Endpoint
   get "/gems/:id" do
diff --git a/spec/bundler/support/artifice/endpoint_redirect.rb b/spec/bundler/support/artifice/endpoint_redirect.rb
index ebf01458ba..ee97fccf64 100644
--- a/spec/bundler/support/artifice/endpoint_redirect.rb
+++ b/spec/bundler/support/artifice/endpoint_redirect.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_strict_basic_authentication.rb b/spec/bundler/support/artifice/endpoint_strict_basic_authentication.rb
index 905a519f3f..4d4da08770 100644
--- a/spec/bundler/support/artifice/endpoint_strict_basic_authentication.rb
+++ b/spec/bundler/support/artifice/endpoint_strict_basic_authentication.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint", __FILE__)
+require_relative "endpoint"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/endpoint_timeout.rb b/spec/bundler/support/artifice/endpoint_timeout.rb
index 3f60471c90..c118da1893 100644
--- a/spec/bundler/support/artifice/endpoint_timeout.rb
+++ b/spec/bundler/support/artifice/endpoint_timeout.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../endpoint_fallback", __FILE__)
+require_relative "endpoint_fallback"
 
 Artifice.deactivate
 
diff --git a/spec/bundler/support/artifice/vcr.rb b/spec/bundler/support/artifice/vcr.rb
index 1e3809ff62..a46f8e9391 100644
--- a/spec/bundler/support/artifice/vcr.rb
+++ b/spec/bundler/support/artifice/vcr.rb
@@ -1,8 +1,9 @@
 # frozen_string_literal: true
 
 require "net/http"
+require_relative "../path"
 
-CASSETTE_PATH = File.expand_path("../vcr_cassettes", __FILE__)
+CASSETTE_PATH = "#{Spec::Path.spec_dir}/support/artifice/vcr_cassettes"
 CASSETTE_NAME = ENV.fetch("BUNDLER_SPEC_VCR_CASSETTE_NAME") { "realworld" }
 
 class BundlerVCRHTTP < Net::HTTP
diff --git a/spec/bundler/support/artifice/windows.rb b/spec/bundler/support/artifice/windows.rb
index 0630798df0..ce7455b86c 100644
--- a/spec/bundler/support/artifice/windows.rb
+++ b/spec/bundler/support/artifice/windows.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require File.expand_path("../../path.rb", __FILE__)
+require_relative "../path"
 include Spec::Path
 
 $LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gems.join("gems/{artifice,mustermann,rack,tilt,sinatra}-*/lib")].map(&:to_s))
diff --git a/spec/bundler/support/command_execution.rb b/spec/bundler/support/command_execution.rb
index cec531d6c3..b3c289979f 100644
--- a/spec/bundler/support/command_execution.rb
+++ b/spec/bundler/support/command_execution.rb
@@ -1,12 +1,7 @@
 # frozen_string_literal: true
 
-require "support/helpers"
-require "support/path"
-
 module Spec
   CommandExecution = Struct.new(:command, :working_directory, :exitstatus, :stdout, :stderr) do
-    include RSpec::Matchers::Composable
-
     def to_s
       c = Shellwords.shellsplit(command.strip).map {|s| s.include?("\n") ? " \\\n  <<EOS\n#{s.gsub(/^/, "  ").chomp}\nEOS" : Shellwords.shellescape(s) }
       c = c.reduce("") do |acc, elem|
diff --git a/spec/bundler/support/filters.rb b/spec/bundler/support/filters.rb
new file mode 100644
index 0000000000..4ce6648cdc
--- /dev/null
+++ b/spec/bundler/support/filters.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+require_relative "sudo"
+
+class RequirementChecker < Proc
+  def self.against(present)
+    provided = Gem::Version.new(present)
+
+    new do |required|
+      !Gem::Requirement.new(required).satisfied_by?(provided)
+    end.tap do |checker|
+      checker.provided = provided
+    end
+  end
+
+  attr_accessor :provided
+
+  def inspect
+    "\"!= #{provided}\""
+  end
+end
+
+RSpec.configure do |config|
+  if ENV["BUNDLER_SUDO_TESTS"] && Spec::Sudo.present?
+    config.filter_run :sudo => true
+  else
+    config.filter_run_excluding :sudo => true
+  end
+
+  if ENV["BUNDLER_REALWORLD_TESTS"]
+    config.filter_run :realworld => true
+  else
+    config.filter_run_excluding :realworld => true
+  end
+
+  git_version = Bundler::Source::Git::GitProxy.new(nil, nil, nil).version
+
+  config.filter_run_excluding :rubygems => RequirementChecker.against(Gem::VERSION)
+  config.filter_run_excluding :git => RequirementChecker.against(git_version)
+  config.filter_run_excluding :bundler => RequirementChecker.against(Bundler::VERSION.split(".")[0])
+  config.filter_run_excluding :ruby_repo => !ENV["GEM_COMMAND"].nil?
+  config.filter_run_excluding :no_color_tty => Gem.win_platform? || !ENV["GITHUB_ACTION"].nil?
+
+  config.filter_run_when_matching :focus unless ENV["CI"]
+end
diff --git a/spec/bundler/support/helpers.rb b/spec/bundler/support/helpers.rb
index 0c05789946..8bf76bba89 100644
--- a/spec/bundler/support/helpers.rb
+++ b/spec/bundler/support/helpers.rb
@@ -2,6 +2,9 @@
 
 require "open3"
 
+require_relative "command_execution"
+require_relative "the_bundle"
+
 module Spec
   module Helpers
     def reset!
@@ -16,8 +19,6 @@ module Spec
       FileUtils.mkdir_p(home)
       FileUtils.mkdir_p(tmpdir)
       Bundler.reset!
-      Bundler.ui = nil
-      Bundler.ui # force it to initialize
     end
 
     def self.bang(method)
@@ -77,7 +78,7 @@ module Spec
     def run(cmd, *args)
       opts = args.last.is_a?(Hash) ? args.pop : {}
       groups = args.map(&:inspect).join(", ")
-      setup = "require '#{lib}/bundler' ; Bundler.setup(#{groups})\n"
+      setup = "require '#{lib_dir}/bundler' ; Bundler.ui.silence { Bundler.setup(#{groups}) }\n"
       ruby(setup + cmd, opts)
     end
     bang :run
@@ -95,10 +96,6 @@ module Spec
       run(cmd, *args)
     end
 
-    def spec
-      spec_dir.to_s
-    end
-
     def bundle(cmd, options = {})
       with_sudo = options.delete(:sudo)
       sudo = with_sudo == :preserve_env ? "sudo -E" : "sudo" if with_sudo
@@ -113,6 +110,7 @@ module Spec
       env["PATH"].gsub!("#{Path.root}/exe", "") if env["PATH"] && system_bundler
 
       requires = options.delete(:requires) || []
+      requires << "support/rubygems"
       requires << "support/hax"
 
       artifice = options.delete(:artifice) do
@@ -123,14 +121,14 @@ module Spec
         end
       end
       if artifice
-        requires << File.expand_path("../artifice/#{artifice}", __FILE__)
+        requires << "support/artifice/#{artifice}"
       end
 
       requires_str = requires.map {|r| "-r#{r}" }.join(" ")
 
       load_path = []
-      load_path << lib unless system_bundler
-      load_path << spec
+      load_path << lib_dir unless system_bundler
+      load_path << spec_dir
       load_path_str = "-I#{load_path.join(File::PATH_SEPARATOR)}"
 
       args = options.map do |k, v|
@@ -146,7 +144,7 @@ module Spec
         end
       end.join
 
-      cmd = "#{sudo} #{Gem.ruby} #{load_path_str} #{requires_str} #{bundle_bin} #{cmd}#{args}"
+      cmd = "#{sudo} #{Gem.ruby} --disable-gems #{load_path_str} #{requires_str} #{bundle_bin} #{cmd}#{args}"
       sys_exec(cmd, env) {|i, o, thr| yield i, o, thr if block_given? }
     end
     bang :bundle
@@ -174,10 +172,10 @@ module Spec
     end
 
     def ruby(ruby, options = {})
-      env = (options.delete(:env) || {}).map {|k, v| "#{k}='#{v}' " }.join
+      env = options.delete(:env) || {}
       ruby = ruby.gsub(/["`\$]/) {|m| "\\#{m}" }
-      lib_option = options[:no_lib] ? "" : " -I#{lib}"
-      sys_exec(%(#{env}#{Gem.ruby}#{lib_option} -e "#{ruby}"))
+      lib_option = options[:no_lib] ? "" : " -I#{lib_dir}"
+      sys_exec(%(#{Gem.ruby}#{lib_option} -e "#{ruby}"), env)
     end
     bang :ruby
 
@@ -193,7 +191,7 @@ module Spec
 
     def gembin(cmd)
       old = ENV["RUBYOPT"]
-      ENV["RUBYOPT"] = "#{ENV["RUBYOPT"]} -I#{lib}"
+      ENV["RUBYOPT"] = "#{ENV["RUBYOPT"]} -I#{lib_dir}"
       cmd = bundled_app("bin/#{cmd}") unless cmd.to_s.include?("/")
       sys_exec(cmd.to_s)
     ensure
@@ -513,10 +511,6 @@ module Spec
       Dir.chdir(path) { `git rev-parse HEAD`.strip }
     end
 
-    def capture_output
-      capture(:stdout)
-    end
-
     def with_read_only(pattern)
       chmod = lambda do |dirmode, filemode|
         lambda do |f|
diff --git a/spec/bundler/support/matchers.rb b/spec/bundler/support/matchers.rb
index b0493801e8..69d3be4a3d 100644
--- a/spec/bundler/support/matchers.rb
+++ b/spec/bundler/support/matchers.rb
@@ -1,7 +1,8 @@
 # frozen_string_literal: true
 
 require "forwardable"
-require "support/the_bundle"
+require_relative "the_bundle"
+
 module Spec
   module Matchers
     extend RSpec::Matchers
@@ -170,7 +171,7 @@ module Spec
               end
             R
           rescue StandardError => e
-            next "checking for #{name} failed:\n#{e}"
+            next "checking for #{name} failed:\n#{e}\n#{e.backtrace.join("\n")}"
           end
           next if out == "WIN"
           next "expected #{name} to not be installed, but it was" if version.nil?
diff --git a/spec/bundler/support/path.rb b/spec/bundler/support/path.rb
index db28454792..b957e24abe 100644
--- a/spec/bundler/support/path.rb
+++ b/spec/bundler/support/path.rb
@@ -22,7 +22,7 @@ module Spec
     end
 
     def gem_bin
-      @gem_bin ||= ruby_core? ? ENV["GEM_COMMAND"] : "#{Gem.ruby} -S gem --backtrace"
+      @gem_bin ||= ruby_core? ? ENV["GEM_COMMAND"] : "#{Gem.ruby} --disable-gems -r#{spec_dir}/support/rubygems -S gem --backtrace"
     end
 
     def spec_dir
@@ -131,7 +131,7 @@ module Spec
       tmp("libs", *args)
     end
 
-    def lib
+    def lib_dir
       root.join("lib")
     end
 
diff --git a/spec/bundler/support/requirement_checker.rb b/spec/bundler/support/requirement_checker.rb
deleted file mode 100644
index e6bd0eb50d..0000000000
--- a/spec/bundler/support/requirement_checker.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-# frozen_string_literal: true
-
-class RequirementChecker < Proc
-  def self.against(present)
-    provided = Gem::Version.new(present)
-
-    new do |required|
-      !Gem::Requirement.new(required).satisfied_by?(provided)
-    end.tap do |checker|
-      checker.provided = provided
-    end
-  end
-
-  attr_accessor :provided
-
-  def inspect
-    "\"!= #{provided}\""
-  end
-end
diff --git a/spec/bundler/support/rubygems.rb b/spec/bundler/support/rubygems.rb
new file mode 100644
index 0000000000..e60f9a928e
--- /dev/null
+++ b/spec/bundler/support/rubygems.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+require_relative "rubygems_version_manager"
+
+RubygemsVersionManager.new(ENV["RGV"]).switch
+
+require "rubygems"
diff --git a/spec/bundler/support/rubygems_ext.rb b/spec/bundler/support/rubygems_ext.rb
index faa474a917..1093362d81 100644
--- a/spec/bundler/support/rubygems_ext.rb
+++ b/spec/bundler/support/rubygems_ext.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require "rubygems/user_interaction"
 require_relative "path"
 require "fileutils"
 
@@ -29,7 +28,9 @@ module Spec
       "ruby-graphviz" => ">= 0.a",
     }.freeze
 
-    def self.dev_setup
+    extend self
+
+    def dev_setup
       deps = DEV_DEPS
 
       # JRuby can't build ronn, so we skip that
@@ -38,22 +39,17 @@ module Spec
       install_gems(deps)
     end
 
-    def self.gem_load(gem_name, bin_container)
-      gem_activate(gem_name)
-      load Gem.bin_path(gem_name, bin_container)
+    def gem_load(gem_name, bin_container)
+      require_relative "rubygems"
+      gem_load_and_activate(gem_name, bin_container)
     end
 
-    def self.gem_activate(gem_name)
-      gem_requirement = DEV_DEPS[gem_name]
-      gem gem_name, gem_requirement
-    end
-
-    def self.gem_require(gem_name)
+    def gem_require(gem_name)
       gem_activate(gem_name)
       require gem_name
     end
 
-    def self.setup
+    def setup
       Gem.clear_paths
 
       ENV["BUNDLE_PATH"] = nil
@@ -71,20 +67,37 @@ module Spec
         manifest_path.open("w") {|f| f << manifest.join }
       end
 
+      FileUtils.mkdir_p(Path.home)
+      FileUtils.mkdir_p(Path.tmpdir)
+
       ENV["HOME"] = Path.home.to_s
       ENV["TMPDIR"] = Path.tmpdir.to_s
 
+      require "rubygems/user_interaction"
       Gem::DefaultUserInteraction.ui = Gem::SilentUI.new
     end
 
-    def self.install_gems(gems)
+  private
+
+    def gem_load_and_activate(gem_name, bin_container)
+      gem_activate(gem_name)
+      load Gem.bin_path(gem_name, bin_container)
+    rescue Gem::LoadError => e
+      abort "We couln't activate #{gem_name} (#{e.requirement}). Run `gem install #{gem_name}:'#{e.requirement}'`"
+    end
+
+    def gem_activate(gem_name)
+      gem_requirement = DEV_DEPS[gem_name]
+      gem gem_name, gem_requirement
+    end
+
+    def install_gems(gems)
       reqs, no_reqs = gems.partition {|_, req| !req.nil? && !req.split(" ").empty? }
       no_reqs.map!(&:first)
       reqs.map! {|name, req| "'#{name}:#{req}'" }
       deps = reqs.concat(no_reqs).join(" ")
       gem = Path.gem_bin
       cmd = "#{gem} install #{deps} --no-document --conservative"
-      puts cmd
       system(cmd) || raise("Installing gems #{deps} for the tests to use failed!")
     end
   end
diff --git a/spec/bundler/support/rubygems_version_manager.rb b/spec/bundler/support/rubygems_version_manager.rb
new file mode 100644
index 0000000000..31f7cc4b08
--- /dev/null
+++ b/spec/bundler/support/rubygems_version_manager.rb
@@ -0,0 +1,127 @@
+# frozen_string_literal: true
+
+require "pathname"
+require_relative "helpers"
+require_relative "path"
+
+class RubygemsVersionManager
+  include Spec::Helpers
+  include Spec::Path
+
+  def initialize(env_version)
+    @env_version = env_version
+  end
+
+  def switch
+    return if use_system?
+
+    unrequire_rubygems_if_needed
+
+    switch_local_copy_if_needed
+
+    prepare_environment
+  end
+
+private
+
+  def use_system?
+    @env_version.nil?
+  end
+
+  def unrequire_rubygems_if_needed
+    return unless rubygems_unrequire_needed?
+
+    require "rbconfig"
+
+    ruby = File.join(RbConfig::CONFIG["bindir"], RbConfig::CONFIG["ruby_install_name"])
+    ruby << RbConfig::CONFIG["EXEEXT"]
+
+    cmd = [ruby, $0, *ARGV].compact
+    cmd[1, 0] = "--disable-gems"
+
+    exec(ENV, *cmd)
+  end
+
+  def switch_local_copy_if_needed
+    return unless local_copy_switch_needed?
+
+    Dir.chdir(local_copy_path) do
+      sys_exec!("git remote update")
+      sys_exec!("git checkout #{target_tag_version} --quiet")
+    end
+  end
+
+  def prepare_environment
+    $:.unshift File.expand_path("lib", local_copy_path)
+  end
+
+  def rubygems_unrequire_needed?
+    defined?(Gem) && Gem::VERSION != target_gem_version
+  end
+
+  def local_copy_switch_needed?
+    !env_version_is_path? && target_gem_version != local_copy_version
+  end
+
+  def target_gem_version
+    @target_gem_version ||= resolve_target_gem_version
+  end
+
+  def target_tag_version
+    @target_tag_version ||= resolve_target_tag_version
+  end
+
+  def local_copy_version
+    gemspec_contents = File.read(local_copy_path.join("lib/rubygems.rb"))
+    version_regexp = /VERSION = ["'](.*)["']/
+
+    version_regexp.match(gemspec_contents)[1]
+  end
+
+  def local_copy_path
+    @local_copy_path ||= resolve_local_copy_path
+  end
+
+  def resolve_local_copy_path
+    return expanded_env_version if env_version_is_path?
+
+    rubygems_path = root.join("tmp/rubygems")
+
+    unless rubygems_path.directory?
+      rubygems_path.parent.mkpath
+      sys_exec!("git clone https://github.com/rubygems/rubygems.git #{rubygems_path}")
+    end
+
+    rubygems_path
+  end
+
+  def env_version_is_path?
+    expanded_env_version.directory?
+  end
+
+  def expanded_env_version
+    @expanded_env_version ||= Pathname.new(@env_version).expand_path(root)
+  end
+
+  def resolve_target_tag_version
+    return "v#{@env_version}" if @env_version.match(/^\d/)
+
+    return "master" if @env_version == master_gem_version
+
+    @env_version
+  end
+
+  def resolve_target_gem_version
+    return local_copy_version if env_version_is_path?
+
+    return @env_version[1..-1] if @env_version.match(/^v/)
+
+    return master_gem_version if @env_version == "master"
+
+    @env_version
+  end
+
+  def master_gem_version
+    "3.1.0.pre1"
+  end
+end
diff --git a/spec/bundler/support/the_bundle.rb b/spec/bundler/support/the_bundle.rb
index c994eaae78..f252a4515b 100644
--- a/spec/bundler/support/the_bundle.rb
+++ b/spec/bundler/support/the_bundle.rb
@@ -1,11 +1,9 @@
 # frozen_string_literal: true
 
-require "support/helpers"
-require "support/path"
+require_relative "path"
 
 module Spec
   class TheBundle
-    include Spec::Helpers
     include Spec::Path
 
     attr_accessor :bundle_dir