test: reuse baked ONNX dependencies

Signed-off-by: svcnemo-autobot <svcnemo-autobot@nvidia.com>

Author: svcnemo-autobot

tests/functional_tests/L2_ONNX_TRT.sh

@@ -18,11 +18,14 @@ set -xeuo pipefail # Exit immediately if a command exits with a non-zero status
 source "$(dirname -- "${BASH_SOURCE[0]}")/../coverage.sh"
 
 # ONNX export only works with an older transformers version. Install it into a
-# writable overlay rather than mutating the image's root-owned environment.
-TRANSFORMERS_OVERLAY="$XDG_CACHE_HOME/export-deploy/transformers-4.51.3"
-mkdir -p "$TRANSFORMERS_OVERLAY"
-uv pip install --target "$TRANSFORMERS_OVERLAY" transformers==4.51.3
-export PYTHONPATH="$TRANSFORMERS_OVERLAY${PYTHONPATH:+:$PYTHONPATH}"
+# writable overlay rather than mutating the image's root-owned environment,
+# unless the selected CI image already contains the required version.
+if ! python -c 'import transformers; assert transformers.__version__ == "4.51.3"'; then
+    TRANSFORMERS_OVERLAY="$XDG_CACHE_HOME/export-deploy/transformers-4.51.3"
+    mkdir -p "$TRANSFORMERS_OVERLAY"
+    uv pip install --target "$TRANSFORMERS_OVERLAY" transformers==4.51.3
+    export PYTHONPATH="$TRANSFORMERS_OVERLAY${PYTHONPATH:+:$PYTHONPATH}"
+fi
 
 export CUDA_VISIBLE_DEVICES="0,1"
 

tests/unit_tests/deploy/test_coverage.py

@@ -161,5 +161,7 @@ def test_onnx_launcher_keeps_checkout_as_working_directory():
 
     assert "pushd" not in launcher
     assert "popd" not in launcher
+    assert 'transformers.__version__ == "4.51.3"' in launcher
+    assert "if ! python -c" in launcher
     assert 'uv pip install --target "$TRANSFORMERS_OVERLAY" transformers==4.51.3' in launcher
     assert 'export PYTHONPATH="$TRANSFORMERS_OVERLAY${PYTHONPATH:+:$PYTHONPATH}"' in launcher