diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 3bc4b39de5fef..9c45d21186fa6 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -25,7 +25,16 @@ jobs:
         sudo apt-get update
         sudo apt-get install libgbm-dev xvfb
     - run: npm install
-    - run: xvfb-run --auto-servernum npm run ccoverage
+    # XVFB-RUN merges both STDOUT and STDERR, whereas we need only STDERR
+    # Wrap `npm run` in a subshell to redirect STDERR to file.
+    - run: xvfb-run --auto-servernum -- bash -c "npm run ccoverage 2>./chromium-linux-testrun.log"
+      env:
+        DEBUG: "*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: chromium-linux-testrun.log
+        path: chromium-linux-testrun.log
 
   chromium_mac:
     name: "Chromium Mac"
@@ -36,7 +45,14 @@ jobs:
       with:
         node-version: 10.15
     - run: npm install
-    - run: npm run ctest
+    - run: npm run ctest 2>./chromium-mac-testrun.log
+      env:
+        DEBUG: "*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: chromium-mac-testrun.log
+        path: chromium-mac-testrun.log
 
   chromium_win:
     name: "Chromium Win"
@@ -47,7 +63,15 @@ jobs:
       with:
         node-version: 10.15
     - run: npm install
-    - run: npm run ctest
+    - run: npm run ctest 2>./chromium-win-testrun.log
+      shell: bash
+      env:
+        DEBUG: "*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: chromium-win-testrun.log
+        path: chromium-win-testrun.log
 
   webkit_linux:
     name: "WebKit Linux"
@@ -63,7 +87,16 @@ jobs:
         sudo apt-get install libwoff1 libopus0 libwebp6 libwebpdemux2 libenchant1c2a libgudev-1.0-0 libsecret-1-0 libhyphen0 libgdk-pixbuf2.0-0 libegl1 libgles2 libevent-2.1-6 libnotify4 libxslt1.1
         sudo apt-get install xvfb
     - run: npm install
-    - run: xvfb-run --auto-servernum npm run wcoverage
+    # XVFB-RUN merges both STDOUT and STDERR, whereas we need only STDERR
+    # Wrap `npm run` in a subshell to redirect STDERR to file.
+    - run: xvfb-run --auto-servernum -- bash -c "npm run wcoverage 2>./webkit-linux-testrun.log"
+      env:
+        DEBUG: "*,-pw:wrapped*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: webkit-linux-testrun.log
+        path: webkit-linux-testrun.log
 
   webkit_mac:
     name: "WebKit Mac"
@@ -74,7 +107,14 @@ jobs:
       with:
         node-version: 10.15
     - run: npm install
-    - run: npm run wtest
+    - run: npm run wtest 2>./webkit-mac-testrun.log
+      env:
+        DEBUG: "*,-pw:wrapped*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: webkit-mac-testrun.log
+        path: webkit-mac-testrun.log
 
   webkit_win:
     name: "WebKit Win"
@@ -85,9 +125,15 @@ jobs:
       with:
         node-version: 10.15
     - run: npm install
-    - run: npm run wtest -- --verbose
+    - run: npm run wtest -- --verbose 2>./webkit-win-testrun.log
+      shell: bash
       env:
-        DEBUG: "*launch*"
+        DEBUG: "*,-pw:wrapped*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: webkit-win-testrun.log
+        path: webkit-win-testrun.log
 
   firefox_linux:
     name: "Firefox Linux"
@@ -102,7 +148,16 @@ jobs:
         sudo apt-get update
         sudo apt-get install xvfb
     - run: npm install
-    - run: xvfb-run --auto-servernum npm run fcoverage
+    # XVFB-RUN merges both STDOUT and STDERR, whereas we need only STDERR
+    # Wrap `npm run` in a subshell to redirect STDERR to file.
+    - run: xvfb-run --auto-servernum -- bash -c "npm run fcoverage 2>./firefox-linux-testrun.log"
+      env:
+        DEBUG: "*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: firefox-linux-testrun.log
+        path: firefox-linux-testrun.log
 
   firefox_mac:
     name: "Firefox Mac"
@@ -113,7 +168,14 @@ jobs:
       with:
         node-version: 10.15
     - run: npm install
-    - run: npm run ftest
+    - run: npm run ftest 2>./firefox-mac-testrun.log
+      env:
+        DEBUG: "*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: firefox-mac-testrun.log
+        path: firefox-mac-testrun.log
 
   firefox_win:
     name: "Firefox Win"
@@ -124,4 +186,12 @@ jobs:
       with:
         node-version: 10.15
     - run: npm install
-    - run: npm run ftest
+    - run: npm run ftest 2>./firefox-win-testrun.log
+      shell: bash
+      env:
+        DEBUG: "*"
+    - uses: actions/upload-artifact@v1
+      if: failure()
+      with:
+        name: firefox-win-testrun.log
+        path: firefox-win-testrun.log