.github/workflows/ci.yml: debug

Author: bevanjkay

.github/workflows/ci.yml

@@ -103,7 +103,9 @@ jobs:
 
       - name: Clean up CI machine
         if: runner.os == 'macOS'
-        run: brew test-bot --cleanup --only-cleanup-before
+        run: |
+          brew test-bot --cleanup --only-cleanup-before
+          df -hI /dev/disk3s1s1
 
       - name: Cache Homebrew Gems
         id: cache