diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bff030e..e18f1b3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -25,14 +25,20 @@ jobs:
       - name: Install CUDA toolkit (compiler only)
         uses: Jimver/cuda-toolkit@v0.2.19
         with:
-          cuda: '12.6.3'
+          # v0.2.19's version table stops at 12.6.2 — 12.6.3 fails the install
+          # step with "Version not available" before nvcc is ever reached.
+          cuda: '12.6.2'
           method: network
           sub-packages: '["nvcc"]'
       - name: Compile backend_cuda.cu (syntax only, no GPU)
         run: |
           cd c
+          # NOT `nvcc ... | head -40`: a pipeline exits with the status of its
+          # LAST command, so head's 0 masked every nvcc error and the job could
+          # only ever be green. A check that cannot fail is worse than no check —
+          # it buys false confidence in the one file nothing else compiles.
           nvcc -O2 -std=c++17 -arch=sm_80 -c backend_cuda.cu -o /dev/null \
-            -Xcompiler=-Wall,-Wextra 2>&1 | head -40
+            -Xcompiler=-Wall,-Wextra
           echo "CUDA syntax check passed"
 
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