add test which reproduces Shopify#50

test/bootboot_test.rb

@@ -240,6 +240,21 @@ def test_bundle_install_with_different_ruby_updating_gemfile_next_lock_succeeds
     end
   end
 
+  def test_bundle_install_without_specific_ruby_version_succeeds
+    write_gemfile do |file, _dir|
+      # transforms "2.7.7" into "~> 2.7.0" for a non-exact ruby requirement
+      requirement = "~> #{RUBY_VERSION.rpartition(".")[0]}.0"
+      FileUtils.cp("#{file.path}.lock", gemfile_next(file))
+      File.write(file, <<-EOM, mode: "a")
+        ruby '#{requirement}'
+      EOM
+
+      run_bundle_command("install", file.path)
+      run_bundle_command("install", file.path, env: { "DEPENDENCIES_NEXT" => "1" })
+      self.assertions += 2 # both commands have succeeded
+    end
+  end
+
   def test_bundle_install_with_different_ruby_for_installing_gemfile_next_lock_fails
     skip("broken with a newer version of bundler")