diff --git a/lib/solidus_dev_support/extension.rb b/lib/solidus_dev_support/extension.rb
index d192ebd2..28c395ff 100644
--- a/lib/solidus_dev_support/extension.rb
+++ b/lib/solidus_dev_support/extension.rb
@@ -2,6 +2,7 @@
 
 require 'thor'
 require 'pathname'
+require 'shellwords'
 
 require 'solidus_dev_support/version'
 
@@ -16,7 +17,7 @@ class Extension < Thor
     def generate(raw_path = '.')
       self.path = raw_path
 
-      empty_directory path
+      run "git init #{path.shellescape} --quiet"
 
       directory 'app', "#{path}/app"
       directory 'lib', "#{path}/lib"
diff --git a/lib/solidus_dev_support/rake_tasks.rb b/lib/solidus_dev_support/rake_tasks.rb
index c24e04b8..a93d086e 100644
--- a/lib/solidus_dev_support/rake_tasks.rb
+++ b/lib/solidus_dev_support/rake_tasks.rb
@@ -27,12 +27,16 @@ def install
     end
 
     def install_test_app_task
-      require 'rake/clean'
-      require 'spree/testing_support/extension_rake'
-
       ENV['DUMMY_PATH'] = test_app_path.to_s
       ENV['LIB_NAME'] = gemspec.name
 
+      # We need to skip solidus bolt for Solidus v3.2,
+      # otherwise it will try to install it when creating the dummy app.
+      ENV['SKIP_SOLIDUS_BOLT'] = 'true'
+
+      require 'rake/clean'
+      require 'spree/testing_support/extension_rake'
+
       ::CLOBBER.include test_app_path
 
       namespace :extension do
diff --git a/lib/solidus_dev_support/templates/extension/.circleci/config.yml b/lib/solidus_dev_support/templates/extension/.circleci/config.yml
index 28d70ebd..4f308922 100644
--- a/lib/solidus_dev_support/templates/extension/.circleci/config.yml
+++ b/lib/solidus_dev_support/templates/extension/.circleci/config.yml
@@ -17,17 +17,37 @@ jobs:
       - browser-tools/install-chrome
       - solidusio_extensions/run-tests
   run-specs-with-postgres:
-    executor: solidusio_extensions/postgres
+    executor:
+      name: solidusio_extensions/postgres
+      ruby_version: '3.1'
     steps:
+      - checkout
       - browser-tools/install-chrome
-      - solidusio_extensions/run-tests
+      - solidusio_extensions/run-tests-solidus-master
+      - solidusio_extensions/store-test-results
+
   run-specs-with-mysql:
-    executor: solidusio_extensions/mysql
+    executor:
+      name: solidusio_extensions/mysql
+      ruby_version: '3.0'
     steps:
+      - checkout
       - browser-tools/install-chrome
-      - solidusio_extensions/run-tests
+      - solidusio_extensions/run-tests-solidus-current
+      - solidusio_extensions/store-test-results
+
+  run-specs-with-sqlite:
+    executor:
+      name: solidusio_extensions/sqlite
+      ruby_version: '2.7'
+    steps:
+      - checkout
+      - browser-tools/install-chrome
+      - solidusio_extensions/run-tests-solidus-older
+      - solidusio_extensions/store-test-results
+
   lint-code:
-    executor: solidusio_extensions/sqlite-memory
+    executor: solidusio_extensions/sqlite
     steps:
       - solidusio_extensions/lint-code
 
@@ -37,6 +57,7 @@ workflows:
       - run-specs-with-sqlite
       - run-specs-with-postgres
       - run-specs-with-mysql
+      - run-specs-with-sqlite
       - lint-code
 
   "Weekly run specs against master":
@@ -51,3 +72,4 @@ workflows:
       - run-specs-with-sqlite
       - run-specs-with-postgres
       - run-specs-with-mysql
+      - run-specs-with-sqlite
diff --git a/lib/solidus_dev_support/templates/extension/bin/sandbox.tt b/lib/solidus_dev_support/templates/extension/bin/sandbox.tt
index 00f421d6..c43e2b4c 100755
--- a/lib/solidus_dev_support/templates/extension/bin/sandbox.tt
+++ b/lib/solidus_dev_support/templates/extension/bin/sandbox.tt
@@ -1,35 +1,31 @@
 #!/usr/bin/env bash
 
+# Set the extension name
+extension_name="<%= file_name %>"
+
 set -e
 test -z "${DEBUG+empty_string}" || set -x
 
+test -n "$DB" || echo "~~~> Use 'export DB=[postgres|mysql|sqlite3]' to control the DB adapter"
+# Support CircleCI runs in which DB is set to "sqlite" by the extension ORB.
 test "$DB" = "sqlite" && export DB="sqlite3"
+echo '~~~> Using $DB as the database engine'
 
-if [ -z "$SOLIDUS_BRANCH" ]
-then
-  echo "~~> Use 'export SOLIDUS_BRANCH=[master|v3.2|...]' to control the Solidus branch"
-  SOLIDUS_BRANCH="master"
-fi
-echo "~~> Using branch $SOLIDUS_BRANCH of solidus"
-
-if [ -z "$SOLIDUS_FRONTEND" ]
-then
-  echo "~~> Use 'export SOLIDUS_FRONTEND=[solidus_frontend|solidus_starter_frontend]' to control the Solidus frontend"
-  SOLIDUS_FRONTEND="solidus_frontend"
-fi
-echo "~~> Using branch $SOLIDUS_FRONTEND as the solidus frontend"
+test -n "$SOLIDUS_BRANCH" || echo "~~~> Use 'export SOLIDUS_BRANCH=[master|v3.2|...]' to control the Solidus branch"
+echo '~~~> Using branch $SOLIDUS_BRANCH of solidus'
 
-extension_name="<%= file_name %>"
-
-# Stay away from the bundler env of the containing extension.
-function unbundled {
-  ruby -rbundler -e'b = proc {system *ARGV}; Bundler.respond_to?(:with_unbundled_env) ? Bundler.with_unbundled_env(&b) : Bundler.with_clean_env(&b)' -- $@
+# Override bundle in order to stay away from the
+# bundler env of the containing extension.
+function with_unbundled_env {
+  ruby -rbundler -e'Bundler.with_unbundled_env { system *ARGV }' -- $@
 }
 
+echo "~~~> Removing the old sandbox"
 rm -rf ./sandbox
-unbundled bundle exec rails new sandbox \
-  --database="${DB:-sqlite3}" \
-  --skip-bundle \
+
+echo "~~~> Creating a pristine Rails app"
+with_unbundled_env rails new sandbox \
+  --database="$DB" \
   --skip-git \
   --skip-keeps \
   --skip-rc \
@@ -43,36 +39,30 @@ if [ ! -d "sandbox" ]; then
 fi
 
 cd ./sandbox
-cat <<RUBY >> Gemfile
-gem 'solidus', github: 'solidusio/solidus', branch: '$SOLIDUS_BRANCH'
-gem 'rails-i18n'
-gem 'solidus_i18n'
 
-gem '$extension_name', path: '..'
+# Ensure any previous sandbox DB is recreated
+bin/rails db:drop db:create
 
-group :test, :development do
-  platforms :mri do
-    gem 'pry-byebug'
-  end
-end
+echo "~~~> Adding solidus to the Gemfile"
+cat <<RUBY >> Gemfile
+gem 'solidus', github: 'solidusio/solidus', branch: '$BRANCH'
+gem 'pry-byebug', group: [:test, :development], platforms: [:mri]
 RUBY
 
-unbundled bundle install --gemfile Gemfile
-
-unbundled bundle exec rake db:drop db:create
+bundle config local.$extension_name "$PWD/.."
+bundle config gemfile "$PWD/Gemfile"
+with_unbundled_env bundle install
 
-unbundled bundle exec rails generate solidus:install \
-  --auto-accept \
-  --user_class=Spree::User \
-  --enforce_available_locales=true \
-  --with-authentication=<%= file_name != 'solidus_auth_devise' %> \
-  --payment-method=none \
-  --frontend=${SOLIDUS_FRONTEND} \
-  $@
+echo "~~~> Running the solidus:install generator"
+with_unbundled_env bin/rails generate solidus:install --auto-accept $@
 
-unbundled bundle exec rails generate solidus:auth:install --auto-run-migrations
-unbundled bundle exec rails generate ${extension_name}:install --auto-run-migrations
+# If it's already in the bundle we can assume it was installed by solidus:install
+(with_unbundled_env bundle list | grep --quiet $extension_name) || (
+  echo "~~~> Installing the extension" &&
+    with_unbundled_env bundle add $extension_name --path '..' &&
+    with_unbundled_env ./bin/rails generate "${extension_name}:install" --auto-run-migrations
+)
 
 echo
-echo "🚀 Sandbox app successfully created for $extension_name!"
-echo "🧪 This app is intended for test purposes."
+echo "~~~> 🚀 Sandbox app successfully created for $extension_name!"
+echo "~~~> 🧪 This app is intended for test purposes."
diff --git a/solidus_dev_support.gemspec b/solidus_dev_support.gemspec
index 0a0e5510..0272c5be 100644
--- a/solidus_dev_support.gemspec
+++ b/solidus_dev_support.gemspec
@@ -48,6 +48,6 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'solidus_core', ['>= 2.0', '< 4']
   spec.add_dependency 'webdrivers', '>= 4.4'
 
-  spec.add_development_dependency 'bundler'
+  spec.add_development_dependency 'bundler', '>= 2.3.22'
   spec.add_development_dependency 'rake'
 end
diff --git a/spec/features/create_extension_spec.rb b/spec/features/create_extension_spec.rb
index 7a2d1472..f8f0f352 100644
--- a/spec/features/create_extension_spec.rb
+++ b/spec/features/create_extension_spec.rb
@@ -40,8 +40,7 @@ def step(method_name)
 
   def check_solidus_cmd
     cd(tmp_path) do
-      output = `#{solidus_cmd} -h`
-      expect($?).to be_success
+      output = sh "#{solidus_cmd} -h"
       expect(output).to include('Commands:')
     end
   end
@@ -53,8 +52,7 @@ def check_gem_version
 
     cd(tmp_path) do
       gem_version_commands.each do |gem_version_cmd|
-        output = `#{solidus_cmd} #{gem_version_cmd}`
-        expect($?).to be_success
+        output = sh "#{solidus_cmd} #{gem_version_cmd}"
         expect(output).to include("Solidus version #{solidus_version}")
         expect(output).to include("Solidus Dev Support version #{gem_version}")
       end
@@ -63,8 +61,7 @@ def check_gem_version
 
   def check_create_extension
     cd(tmp_path) do
-      output = `#{solidus_cmd} extension #{extension_name}`
-      expect($?).to be_success
+      output = sh "#{solidus_cmd} extension #{extension_name}"
       expect(output).to include(gemspec_name)
       expect(output).to include('.circleci')
     end
@@ -96,7 +93,7 @@ def check_create_extension
 
   def check_bundle_install
     cd(install_path) do
-      open('Gemfile', 'a') { |f| f.puts "gem 'solidus_dev_support', path: '../../..'" }
+      open('Gemfile', 'a') { |f| f.puts "gem 'solidus_dev_support', path: #{gem_root.inspect}" }
     end
 
     expect { bundle_install }.to raise_error(command_failed_error, /invalid gemspec/)
@@ -115,7 +112,7 @@ def check_bundle_install
 
   def check_default_task
     cd(install_path) do
-      output = sh('bin/rake')
+      output = unbundled_sh('bin/rake')
       expect(output).to include('Generating dummy Rails application')
       expect(output).to include('0 examples, 0 failures')
     end
@@ -130,7 +127,7 @@ def check_run_specs
       "require 'spec_helper'\nRSpec.describe 'Some test' do it { expect(true).to be_truthy } end\n"
     )
     cd(install_path) do
-      output = sh('bundle exec rspec')
+      output = unbundled_sh('bundle exec rspec')
       expect(output).to include('loading test_extension factories')
       expect(output).to include('1 example, 0 failures')
       expect(output).to include(ENV['CODECOV_TOKEN'] ? 'Coverage reports upload successfully' : 'Provide a CODECOV_TOKEN environment variable to enable Codecov uploads')
@@ -147,7 +144,7 @@ def check_sandbox
       expect(first_run_output).to include("Creating the sandbox app...")
       expect(first_run_output).to include('The version of SolidusTestExtension is 0.0.1')
 
-      second_run_output = sh(command)
+      second_run_output = unbundled_sh(command)
       expect(second_run_output).not_to include("Creating the sandbox app...")
       expect(second_run_output).to include('The version of SolidusTestExtension is 0.0.1')
     end
@@ -155,9 +152,7 @@ def check_sandbox
 
   def sh(*args)
     command = args.size == 1 ? args.first : args.shelljoin
-    output, status = with_unbundled_env do
-      Open3.capture2e({ 'CI' => nil }, command)
-    end
+    output, status = Open3.capture2e({ 'CI' => nil }, command)
 
     if $DEBUG || ENV['DEBUG']
       warn '~' * 80
@@ -173,12 +168,8 @@ def sh(*args)
     output.to_s
   end
 
-  def with_unbundled_env(&block)
-    if Bundler.respond_to?(:with_unbundled_env)
-      Bundler.with_unbundled_env(&block)
-    else
-      Bundler.with_clean_env(&block)
-    end
+  def unbundled_sh(*args)
+    Bundler.with_unbundled_env { sh(*args) }
   end
 
   def bundle_install
@@ -187,11 +178,11 @@ def bundle_install
     bundle_path = "#{gem_root}/vendor/bundle"
 
     if File.exist?(bundle_path)
-      sh "bundle config set --local path #{bundle_path.shellescape}"
+      unbundled_sh "bundle config set --local path #{bundle_path.shellescape}"
     end
 
     output = nil
-    cd(install_path) { output = sh 'bundle install' }
+    cd(install_path) { output = unbundled_sh 'bundle install' }
     output
   end
 end