nvidia-cudnn-cu12/cublas-cu12 are namespace packages with no __file__, so os.path.dirname() raised TypeError and the install cell aborted. Locate libcublas.so/libcudnn.so under site-packages with find and build LD_LIBRARY_PATH from those. Also add a CTranslate2 GPU check cell (ctranslate2.get_cuda_device_count) right after install so GPU usability is confirmed before transcription.