Failure to hardlink files

[krosenfeld-IDM]

Following @clorton 's instructions for installing:

pip3 install uv
uv venv
source .venv/bin/activate
uv pip install llvmlite numba

I get a warning with the llmvmlite and numba install:

warning: Failed to hardlink files; falling back to full copy. This may lead to degraded performance.
         If the cache and target directories are on different filesystems, hardlinking may not be supported.
         If this is intentional, set `export UV_LINK_MODE=copy` or use `--link-mode=copy` to suppress this warning.

[clorton]

I thought this would be solved with a dependency change in laser-core but it hasn't entirely solved the problem.

• the current default Codespace has NumPy 2.x installed which causes Numba grief.
• One option is to pip uninstall -y numpy==2.1.1 (use pip list | grep numpy to determine the actual version of Numpy) and then pip install --upgrade -e . to get laser-measles dependencies installed.

[krosenfeld-IDM]

It looked like numba had planned to have a NP2 compatible version in June 2024 but doesn't look so. Haven't sussed out the current status / trajectory:
https://numba.discourse.group/t/communicating-numpy-2-0-changes-to-numba-users/2457