Try a relative path

.circleci/config.yml

@@ -55,7 +55,7 @@ jobs:
           version: << parameters.version >>
       - run: bundle exec rake test
       - store_test_results:
-          path: "$CIRCLE_TEST_REPORTS/reports"
+          path: ./reports
 
 workflows:
   version: 2

test/support/circleci.rb

@@ -2,5 +2,5 @@
 if ENV['CIRCLECI']
   require 'minitest/ci'
 
-  Minitest::Ci.report_dir = File.join(ENV.fetch('CIRCLE_TEST_REPORTS'), 'reports')
+  Minitest::Ci.report_dir = './reports'
 end