The prebuilt llama.cpp binary (cuda13-newer) links against
libcudart.so.13 and libcublas.so.13. When torch is installed via pip,
these libraries live in the venv's site-packages under
nvidia/cu13/lib/, not in /usr/local/cuda/.
The existing LD_LIBRARY_PATH logic only searched /usr/local/cuda*
paths (which have CUDA 12.x), so the CUDA backend failed to load
silently and llama-server fell back to CPU -- even with -ngl -1.
This adds a glob scan of the venv's nvidia package directories
(cu*, cudnn, nvjitlink) to LD_LIBRARY_PATH before launching
llama-server, matching where pip puts the CUDA runtime.
Tested on Colab with RTX PRO 6000 Blackwell (CUDA 13.0, pip torch):
before -- 3 MiB GPU, 0% util, CPU inference
after -- 13317 MiB GPU, 77% util, full GPU inference
Co-authored-by: Daniel Han <danielhanchen@users.noreply.github.com>
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