ci: check out test sources at the commit the wheels were built from

.github/workflows/test-wheel-linux.yml

@@ -128,6 +128,10 @@ jobs:
     steps:
       - name: Checkout ${{ github.event.repository.name }}
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          # Test sources must match the wheels under test (nightly runs
+          # reuse wheels built from an older commit of main).
+          ref: ${{ inputs.sha || github.sha }}
 
       - name: Setup proxy cache
         uses: nv-gha-runners/setup-proxy-cache@main

.github/workflows/test-wheel-windows.yml

@@ -107,6 +107,10 @@ jobs:
     steps:
       - name: Checkout ${{ github.event.repository.name }}
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          # Test sources must match the wheels under test (nightly runs
+          # reuse wheels built from an older commit of main).
+          ref: ${{ inputs.sha || github.sha }}
 
       - name: Setup proxy cache
         uses: nv-gha-runners/setup-proxy-cache@main

cuda_bindings/tests/test_cuda.py

@@ -655,6 +655,8 @@ def test_ffi_coverage_jit_option_binary_loader_thread_count():
 def test_ffi_coverage_jit_wall_time_pointer_is_valid():
     """CU_JIT_WALL_TIME must give CUDA a valid writable float address, not a garbage pointer."""
     helper = cuda._HelperCUjit_option(cuda.CUjit_option.CU_JIT_WALL_TIME, 0.0)
+    # Guard against NULL so a regression fails instead of segfaulting.
+    assert helper.cptr != 0
     # Write a sentinel float via ctypes to confirm the pointer is addressable.
     ctypes.c_float.from_address(helper.cptr).value = 3.14
     assert ctypes.c_float.from_address(helper.cptr).value == pytest.approx(3.14, rel=1e-5)