(Chinese version) 中文版使用说明可以看这里：https://yipko.com/posts/work/cuda-switcher-with-conda/

Sometimes, it becomes necessary to switch to an earlier version of CUDA in order to run older code on a machine that is actually set up to use the current version of the CUDA toolkit.

This is as simple as adjusting the values of a few environment variables, yet it is cumbersome to do manually. Therefore, this repository provides the bash script switch-cuda.sh, which adjusts the environment to use a specific version of CUDA for the current bash session.

Notice: switch-cuda.sh has been written for and tested on Ubuntu 16.04, but is easily adapted for other platforms.

source switch-cuda.sh [VERSION]

Notice that the script has to be sourced rather than executed, as it performs changes of environment variables that are supposed to persist after the script has finished.

If a version number is provided, than all relevant environment variables are adjusted to the required CUDA version (including PATH, LD_LIBRARY_PATH, CUDA_HOME, and CUDA_ROOT).

If the special argument default is provided, the script clears these environment variables and restores the system’s default CUDA setup (as determined by the /usr/local/cuda symbolic link).

If no version is provided, however, then the script simply prints all versions of CUDA that have been found on the used machine (in /usr/local).

$ source switch-cuda.sh 
The following CUDA installations have been found (in '/usr/local'):
* cuda-8.0
* cuda-9.0
* cuda-9.1

$ source switch-cuda.sh 9.0
Switched to CUDA 9.0.

$ source switch-cuda.sh default
CUDA environment has been reset to default.

You can automatically switch to a specific CUDA version when activating a conda environment by adding a hook inside the environment’s etc/conda/activate.d and etc/conda/deactivate.d directories.

Example:

Assuming your environment is located at ~/miniconda3/envs/YOUR_ENV_NAME and your "switch-cuda.sh" is located at ~/switch-cuda.sh. The CUDA version you want to use in your environment is 12.1.

Create the following two scripts:

~/miniconda3/envs/YOUR_ENV_NAME/etc/conda/activate.d/set-cuda.sh
~/miniconda3/envs/YOUR_ENV_NAME/etc/conda/deactivate.d/reset-cuda.sh

activate.d/set-cuda.sh

#!/bin/bash
source ~/Projects/switch-cuda.sh 12.1

activate.d/reset-cuda.sh

#!/bin/bash
source ~/Projects/switch-cuda.sh default

Usage

Now, whenever you activate YOUR_ENV_NAME:

conda activate YOUR_ENV_NAME

It will automatically switch to 12.1.

And when you deactivate:

conda deactivate

It will reset back to the system default CUDA setup.