maybe maybe

spec/dummy/spec/rake/assets_precompile_rake_spec.rb

@@ -9,6 +9,7 @@
   it "doesn't show deprecation message for using webpacker:clean task" do
     allow(ENV).to receive(:[]).with(anything).and_call_original
     allow(ENV).to receive(:[]).with("SHAKAPACKER_PRECOMPILE").and_return("false")
+    allow(ENV).to receive(:[]).with("WEBPACKER_PRECOMPILE").and_return("false")
 
     Rails.application.load_tasks
 
@@ -17,7 +18,6 @@
     end
 
     expect do
-      system "bundle install && yarn install && yarn run build:test"
       Rake::Task["assets:precompile"].execute
     end.not_to output(/Consider using `rake shakapacker:clean`/).to_stdout