diff --git a/.github/workflows/build-test.yml b/.github/workflows/build-test.yml
index b85adc95..c99d8ed3 100644
--- a/.github/workflows/build-test.yml
+++ b/.github/workflows/build-test.yml
@@ -93,6 +93,16 @@ jobs:
       DOCKER_OSES: "${{ matrix.DOCKER_OSES }}"
       DOCKER_LANGUAGES: "${{ matrix.DOCKER_LANGUAGES }}"
     steps:
+      - name: "DEBUG: Disk space usage"
+        run: >-
+          du -xh / | sort -rh | tee './var/log/du-root.log' | head -n 100
+      - name: "DEBUG: Upload disk space debugging"
+        uses: "actions/upload-artifact@master"
+        with:
+          name: "debug-disk-space"
+          path: |
+            ./var/log/*
+
       # Shared or common set up:
       - name: "Checkout source from VCS"
         uses: "actions/checkout@master"