diff --git a/.github/workflows/nightly-artifacts.yml b/.github/workflows/nightly-artifacts.yml
index a22b4773..c3a94d7e 100644
--- a/.github/workflows/nightly-artifacts.yml
+++ b/.github/workflows/nightly-artifacts.yml
@@ -111,8 +111,10 @@ jobs:
             exit 1
           fi
 
+      # Also on cancelled(): the job timeout cancels a hanging run, and the reports of the
+      # classes that did finish carry the timed-out tests' full stacks.
       - name: Keep the test reports on a failure
-        if: failure()
+        if: failure() || cancelled()
         uses: actions/upload-artifact@v7
         with:
           name: test-results
diff --git a/.github/workflows/pr-compile-check.yml b/.github/workflows/pr-compile-check.yml
index e0e1239b..982720f8 100644
--- a/.github/workflows/pr-compile-check.yml
+++ b/.github/workflows/pr-compile-check.yml
@@ -286,8 +286,10 @@ jobs:
           if-no-files-found: ignore
           retention-days: 14
 
+      # Also on cancelled(): the job timeout cancels a hanging run, and the reports of the
+      # classes that did finish carry the timed-out tests' full stacks.
       - name: Keep the test reports on a failure
-        if: failure()
+        if: failure() || cancelled()
         uses: actions/upload-artifact@v7
         with:
           name: test-results
diff --git a/.github/workflows/tagged-release.yml b/.github/workflows/tagged-release.yml
index 1818a350..191a7aef 100644
--- a/.github/workflows/tagged-release.yml
+++ b/.github/workflows/tagged-release.yml
@@ -130,8 +130,10 @@ jobs:
             exit 1
           fi
 
+      # Also on cancelled(): the job timeout cancels a hanging run, and the reports of the
+      # classes that did finish carry the timed-out tests' full stacks.
       - name: Keep the test reports on a failure
-        if: failure()
+        if: failure() || cancelled()
         uses: actions/upload-artifact@v7
         with:
           name: test-results
diff --git a/build.gradle.kts b/build.gradle.kts
index bf9eba28..d8629c56 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -151,6 +151,11 @@ subprojects {
          */
         systemProperty("junit.jupiter.execution.timeout.default", "2m")
         systemProperty("junit.jupiter.execution.timeout.thread.mode.default", "SEPARATE_THREAD")
+        // The default short format prints only the first frame of each cause, which for a
+        // timed-out test is the line it hung in but not the call that blocked there.
+        testLogging {
+            exceptionFormat = org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
+        }
         finalizedBy(checkTestUserHome)
     }