diff --git a/Changelog.md b/Changelog.md
index 90c2515d9b..a5b45a06eb 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,5 +1,9 @@
-### Development
-[Full Changelog](http://github.com/rspec/rspec-rails/compare/v3.9.0...master)
+### 3.9.1 / 2020-03-10
+[Full Changelog](http://github.com/rspec/rspec-rails/compare/v3.9.0...v3.9.1)
+
+Bug Fixes:
+
+* Add missing require for have_enqueued_mail matcher. (Ignatius Reza, #2117)
 
 ### 3.9.0 / 2019-10-08
 [Full Changelog](http://github.com/rspec/rspec-rails/compare/v3.8.2...v3.9.0)
diff --git a/Gemfile b/Gemfile
index 03852dce93..89036e90a9 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,12 +7,12 @@ gemspec
 rspec_dependencies_gemfile = File.expand_path("../Gemfile-rspec-dependencies", __FILE__)
 eval_gemfile rspec_dependencies_gemfile
 
-gem 'yard', '~> 0.8.7', :require => false
+gem 'yard', '~> 0.9.24', :require => false
 
 ### deps for rdoc.info
 group :documentation do
-  gem 'redcarpet',     '2.3.0'
-  gem 'github-markup', '1.0.0'
+  gem 'redcarpet'
+  gem 'github-markup'
   if RUBY_VERSION > '2.0.0'
     gem 'relish'
   end
diff --git a/Gemfile-rails-dependencies b/Gemfile-rails-dependencies
index a849eeeda4..9d9bd20849 100644
--- a/Gemfile-rails-dependencies
+++ b/Gemfile-rails-dependencies
@@ -1,4 +1,10 @@
 version_file = File.expand_path("../.rails-version", __FILE__)
+
+# FIXME: rack 2.1.0 introduces a deprecation warning that rails is triggering,
+# but in later versions this warning will be removed. Get rid of this hack once
+# rack 2.1.0+ is out.
+gem 'rack', '!= 2.1.0'
+
 case version = ENV['RAILS_VERSION'] || (File.exist?(version_file) && File.read(version_file).chomp) || ''
 when /master/
   gem "rails", :git => "https://github.com/rails/rails.git"
@@ -43,6 +49,16 @@ else
   if version >= '5-1-stable' && RUBY_VERSION  >= "2.2"
     gem "puma"
   end
+
+  if RUBY_VERSION < "2.5"
+    gem "sprockets", "~> 3.0"
+  end
+
+  if version.gsub(/[^\d\.]/,'').to_f >= 6.0
+    gem "activerecord-jdbcsqlite3-adapter", "~> 60.0.rc1", :platforms => [:jruby]
+  else
+    gem 'activerecord-jdbcsqlite3-adapter', :platforms => [:jruby]
+  end
 end
 
 gem "i18n", '< 0.7.0' if RUBY_VERSION < '1.9.3'
diff --git a/README.md b/README.md
index 0484f8cda2..bb8726e71a 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ Use **[`rspec-rails` 1.x][]** for Rails 2.x.
    ```ruby
    # Run against the latest stable release
    group :development, :test do
-     gem 'rspec-rails', '~> 3.8'
+     gem 'rspec-rails', '~> 3.9'
    end
 
    # Or, run against the master branch
diff --git a/appveyor.yml b/appveyor.yml
index b2fac867df..68756416f9 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,4 +1,4 @@
-# This file was generated on 2019-07-24T15:33:53+02:00 from the rspec-dev repo.
+# This file was generated on 2019-12-18T14:01:39+00:00 from the rspec-dev repo.
 # DO NOT modify it by hand as your changes will get lost the next time it is generated.
 
 version: "{build}"
diff --git a/example_app_generator/spec/verify_mailer_preview_path_spec.rb b/example_app_generator/spec/verify_mailer_preview_path_spec.rb
index a2b48b01c0..b6217dacf5 100644
--- a/example_app_generator/spec/verify_mailer_preview_path_spec.rb
+++ b/example_app_generator/spec/verify_mailer_preview_path_spec.rb
@@ -25,6 +25,7 @@ def capture_exec(*ops)
     # Necessary to ignore warnings from Rails code base
     out =  io.readlines.
               reject { |line| line =~ /warning: circular argument reference/ }.
+              reject { |line| line =~ /Gem::Specification#rubyforge_project=/ }.
               join.
               chomp
     CaptureExec.new(out, $?.exitstatus)
diff --git a/features/job_specs/job_spec.feature b/features/job_specs/job_spec.feature
index 00850f7fb3..d195893a82 100644
--- a/features/job_specs/job_spec.feature
+++ b/features/job_specs/job_spec.feature
@@ -1,11 +1,8 @@
 Feature: job spec
 
-  Job specs provide alternative assertions to those available in
-  `ActiveJob::TestHelper` and help assert behaviour of the jobs themselves
-  and that other entities correctly enqueue them.
+  Job specs provide alternative assertions to those available in `ActiveJob::TestHelper` and help assert behaviour of the jobs themselves and that other entities correctly enqueue them.
 
-  Job specs are marked by `:type => :job` or if you have set
-  `config.infer_spec_type_from_file_location!` by placing them in `spec/jobs`.
+  Job specs are marked by `:type => :job` or if you have set `config.infer_spec_type_from_file_location!` by placing them in `spec/jobs`.
 
   With job specs, you can:
 
@@ -14,10 +11,7 @@ Feature: job spec
   * specify when the job was enqueued until
   * specify the queue which the job was enqueued to
 
-  Check the documentation on
-  [`have_been_enqueued`](matchers/have-been-enqueued-matcher) and
-  [`have_enqueued_job`](matchers/have-enqueued-job-matcher) for more
-  information.
+  Check the documentation on [`have_been_enqueued`](../matchers/have-been-enqueued-matcher), [`have_enqueued_job`](../matchers/have-enqueued-job-matcher) for more information.
 
   Background:
     Given active job is available
diff --git a/features/support/env.rb b/features/support/env.rb
index a79a4e1b4f..d4d96ebb81 100644
--- a/features/support/env.rb
+++ b/features/support/env.rb
@@ -2,23 +2,41 @@
 require 'fileutils'
 
 module ArubaExt
-  def run(cmd, timeout = nil)
+  def run_command(cmd, timeout = nil)
     exec_cmd = cmd =~ /^rspec/ ? "bin/#{cmd}" : cmd
-    super(exec_cmd, timeout)
+    unset_bundler_env_vars
+    # Ensure the correct Gemfile and binstubs are found
+    in_current_directory do
+      with_unbundled_env do
+        super(exec_cmd, timeout)
+      end
+    end
   end
-  # This method over rides Aruba 0.5.4 implementation so that we can reset Bundler to use the sample app Gemfile
-  def in_current_dir(&block)
-    Bundler.with_clean_env do
-      _mkdir(current_dir)
-      Dir.chdir(current_dir, &block)
+
+  def unset_bundler_env_vars
+    empty_env = with_environment { with_unbundled_env { ENV.to_h } }
+    aruba_env = aruba.environment.to_h
+    (aruba_env.keys - empty_env.keys).each do |key|
+      delete_environment_variable key
+    end
+    empty_env.each do |k, v|
+      set_environment_variable k, v
+    end
+  end
+
+  def with_unbundled_env
+    if Bundler.respond_to?(:with_unbundled_env)
+      Bundler.with_unbundled_env { yield }
+    else
+      Bundler.with_clean_env { yield }
     end
   end
 end
 
 World(ArubaExt)
 
-Before do
-  @aruba_timeout_seconds = 30
+Aruba.configure do |config|
+  config.exit_timeout = 30
 end
 
 unless File.directory?('./tmp/example_app')
diff --git a/lib/rspec/rails/matchers.rb b/lib/rspec/rails/matchers.rb
index dd37321e80..1602654af3 100644
--- a/lib/rspec/rails/matchers.rb
+++ b/lib/rspec/rails/matchers.rb
@@ -22,4 +22,5 @@ module Matchers
 require 'rspec/rails/matchers/have_http_status'
 if RSpec::Rails::FeatureCheck.has_active_job?
   require 'rspec/rails/matchers/active_job'
+  require 'rspec/rails/matchers/have_enqueued_mail'
 end
diff --git a/lib/rspec/rails/version.rb b/lib/rspec/rails/version.rb
index f93a1ab82e..282e11a0b9 100644
--- a/lib/rspec/rails/version.rb
+++ b/lib/rspec/rails/version.rb
@@ -3,7 +3,7 @@ module Rails
     # Version information for RSpec Rails.
     module Version
       # Current version of RSpec Rails, in semantic versioning format.
-      STRING = '3.9.0'
+      STRING = '3.9.1'
     end
   end
 end
diff --git a/rspec-rails.gemspec b/rspec-rails.gemspec
index 8086d7818e..d9ef49b90a 100644
--- a/rspec-rails.gemspec
+++ b/rspec-rails.gemspec
@@ -51,6 +51,6 @@ Gem::Specification.new do |s|
   end
 
   s.add_development_dependency 'cucumber', '~> 1.3.5'
-  s.add_development_dependency 'aruba',    '~> 0.5.4'
+  s.add_development_dependency 'aruba',    '~> 0.14.12'
   s.add_development_dependency 'ammeter',  '~> 1.1.2'
 end
diff --git a/script/after_update_travis_build.sh b/script/after_update_travis_build.sh
index 61b7bc5486..b2171dfaa4 100755
--- a/script/after_update_travis_build.sh
+++ b/script/after_update_travis_build.sh
@@ -3,3 +3,6 @@ set -e
 
 echo "Restoring custom Travis config"
 mv .travis.yml{.update_backup,}
+
+echo "Removing Base rubocop, Rspec-Rails does not use it"
+rm '.rubocop_rspec_base.yml'
diff --git a/script/clone_all_rspec_repos b/script/clone_all_rspec_repos
index 70b9e0a4e7..64f4ee8f5d 100755
--- a/script/clone_all_rspec_repos
+++ b/script/clone_all_rspec_repos
@@ -1,5 +1,5 @@
 #!/bin/bash
-# This file was generated on 2019-07-24T15:33:53+02:00 from the rspec-dev repo.
+# This file was generated on 2019-12-18T14:01:39+00:00 from the rspec-dev repo.
 # DO NOT modify it by hand as your changes will get lost the next time it is generated.
 
 set -e
diff --git a/script/downgrade_bundler_on_old_rails b/script/downgrade_bundler_on_old_rails
index c86d3762f1..ae59f78626 100755
--- a/script/downgrade_bundler_on_old_rails
+++ b/script/downgrade_bundler_on_old_rails
@@ -12,7 +12,7 @@ if ruby -e "exit(ENV['RAILS_VERSION'].scan(/\d+\.\d+.\d+/)[0].to_f < 5)"; then
   gem uninstall -aIx bundler || echo "Warning error occured removing bundler via gem"
 
   # this only works on Ruby 2.3 which is luckily the version we need to fix
-  if is_ruby_23; then
+  if ruby -e "exit(RUBY_VERSION.to_f == 2.3)"; then
     rvm @global do gem uninstall -aIx bundler
   fi
 
diff --git a/script/functions.sh b/script/functions.sh
index 32b2d66a8f..ba9305efba 100644
--- a/script/functions.sh
+++ b/script/functions.sh
@@ -1,4 +1,4 @@
-# This file was generated on 2019-07-24T15:33:53+02:00 from the rspec-dev repo.
+# This file was generated on 2019-12-18T14:01:39+00:00 from the rspec-dev repo.
 # DO NOT modify it by hand as your changes will get lost the next time it is generated.
 
 SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
@@ -6,7 +6,7 @@ source $SCRIPT_DIR/travis_functions.sh
 source $SCRIPT_DIR/predicate_functions.sh
 
 # If JRUBY_OPTS isn't set, use these.
-# see http://docs.travis-ci.com/user/ci-environment/
+# see https://docs.travis-ci.com/user/ci-environment/
 export JRUBY_OPTS=${JRUBY_OPTS:-"--server -Xcompile.invokedynamic=false"}
 SPECS_HAVE_RUN_FILE=specs.out
 MAINTENANCE_BRANCH=`cat maintenance-branch`
@@ -187,7 +187,9 @@ function run_all_spec_suites {
   fold "rspec-core specs" run_spec_suite_for "rspec-core"
   fold "rspec-expectations specs" run_spec_suite_for "rspec-expectations"
   fold "rspec-mocks specs" run_spec_suite_for "rspec-mocks"
-  fold "rspec-rails specs" run_spec_suite_for "rspec-rails"
+  if rspec_rails_compatible; then
+    fold "rspec-rails specs" run_spec_suite_for "rspec-rails"
+  fi
 
   if rspec_support_compatible; then
     fold "rspec-support specs" run_spec_suite_for "rspec-support"
diff --git a/script/predicate_functions.sh b/script/predicate_functions.sh
index e2f4ac24cc..9b8616145a 100644
--- a/script/predicate_functions.sh
+++ b/script/predicate_functions.sh
@@ -1,4 +1,4 @@
-# This file was generated on 2019-07-24T15:33:53+02:00 from the rspec-dev repo.
+# This file was generated on 2019-12-18T14:01:39+00:00 from the rspec-dev repo.
 # DO NOT modify it by hand as your changes will get lost the next time it is generated.
 
 function is_mri {
@@ -69,16 +69,16 @@ function is_mri_2plus {
   fi
 }
 
-function is_ruby_23 {
-  if ruby -e "exit(RUBY_VERSION.to_f == 2.3)"; then
+function is_ruby_23_plus {
+  if ruby -e "exit(RUBY_VERSION.to_f >= 2.3)"; then
     return 0
   else
     return 1
   fi
 }
 
-function is_ruby_23_plus {
-  if ruby -e "exit(RUBY_VERSION.to_f >= 2.3)"; then
+function rspec_rails_compatible {
+  if is_ruby_23_plus; then
     return 0
   else
     return 1
diff --git a/script/run_build b/script/run_build
index a4a5c3dc01..277e7f27d0 100755
--- a/script/run_build
+++ b/script/run_build
@@ -1,5 +1,5 @@
 #!/bin/bash
-# This file was generated on 2019-07-24T15:33:53+02:00 from the rspec-dev repo.
+# This file was generated on 2019-12-18T14:01:39+00:00 from the rspec-dev repo.
 # DO NOT modify it by hand as your changes will get lost the next time it is generated.
 
 set -e
diff --git a/script/travis_functions.sh b/script/travis_functions.sh
index 15cc10279f..4a86428a6b 100644
--- a/script/travis_functions.sh
+++ b/script/travis_functions.sh
@@ -1,4 +1,4 @@
-# This file was generated on 2019-07-24T15:33:53+02:00 from the rspec-dev repo.
+# This file was generated on 2019-12-18T14:01:39+00:00 from the rspec-dev repo.
 # DO NOT modify it by hand as your changes will get lost the next time it is generated.
 
 # Taken from:
diff --git a/script/update_rubygems_and_install_bundler b/script/update_rubygems_and_install_bundler
index 8dbe307dd5..a6b4a95925 100755
--- a/script/update_rubygems_and_install_bundler
+++ b/script/update_rubygems_and_install_bundler
@@ -1,13 +1,19 @@
 #!/bin/bash
-# This file was generated on 2019-07-24T15:33:53+02:00 from the rspec-dev repo.
+# This file was generated on 2019-12-18T14:01:39+00:00 from the rspec-dev repo.
 # DO NOT modify it by hand as your changes will get lost the next time it is generated.
 
 set -e
 source script/functions.sh
 
 if is_ruby_23_plus; then
-  gem update --system
-  gem install bundler
+  if ruby -e "exit(ENV['RAILS_VERSION'].scan(/\d+\.\d+.\d+/)[0].to_f >= 5)"; then
+    yes | gem update --system
+    yes | gem install bundler
+  else
+    echo "Warning installing older versions of Rubygems / Bundler"
+    gem update --system '2.7.8'
+    gem install bundler -v '1.17.3'
+  fi
 else
   echo "Warning installing older versions of Rubygems / Bundler"
   gem update --system '2.7.8'
diff --git a/spec/sanity_check_spec.rb b/spec/sanity_check_spec.rb
index cb32e406fb..c7aed44f6f 100644
--- a/spec/sanity_check_spec.rb
+++ b/spec/sanity_check_spec.rb
@@ -7,6 +7,14 @@
 
   before{ FileUtils.mkdir_p tmp_root }
 
+  def with_clean_env
+    if Bundler.respond_to?(:with_unbundled_env)
+      Bundler.with_unbundled_env { yield }
+    else
+      Bundler.with_clean_env { yield }
+    end
+  end
+
   it "fails when libraries are not required" do
     script = tmp_root.join("fail_sanity_check")
     File.open(script, "w") do |f|
@@ -17,7 +25,7 @@
     end
     FileUtils.chmod 0777, script
 
-    Bundler.with_clean_env do
+    with_clean_env do
       expect(`bundle exec #{script} 2>&1`).
         to match(/uninitialized constant RSpec::Support/).
         or match(/undefined method `require_rspec_core' for RSpec::Support:Module/)
@@ -26,7 +34,7 @@
     end
   end
 
-  it "passes when libraries are required" do
+  it "passes when libraries are required", :unless => RSpec::Support::Ruby.jruby? do
     script = tmp_root.join("pass_sanity_check")
     File.open(script, "w") do |f|
       f.write <<-EOF.gsub(/^\s+\|/, '')
@@ -38,7 +46,7 @@
     end
     FileUtils.chmod 0777, script
 
-    Bundler.with_clean_env do
+    with_clean_env do
       expect(`bundle exec #{script} 2>&1`).to be_empty
       expect($?.exitstatus).to eq(0)
     end