The `throwIf` expression in CUDNN was evaluated eagerly and essentially prevented the use of cudaPackages without a supported version of CUDNN (even when CUDNN was not requested).
This is a hot-fix to un-break cuda-enabled packages (like tensorflow,
jaxlib, faiss, opencv, ...) after the gcc11->gcc12 bump. We should
probably build the whole downstream packages with a compatible stdenv
(such as gcc11Stdenv for cudaPackages_11), but just pointing nvcc at the
right compiler seems to do the trick
We already used this hack for non-redist cudatoolkit. Now we use it more
consistently.
This commit also re-links cuda packages against libstdc++ from the same
"compatible" gcc, rather than the current stdenv. We didn't test if this
is necessary -> need to revise in further PRs.
NOTE: long-term we should make it possible to override -ccbin and use
e.g. clang
There are many different versions of the `cudatoolkit` and related
cuda packages, and it can be tricky to ensure they remain compatible.
- `cudaPackages` is now a package set with `cudatoolkit`, `cudnn`, `cutensor`, `nccl`, as well as `cudatoolkit` split into smaller packages ("redist");
- expressions should now use `cudaPackages` as parameter instead of the individual cuda packages;
- `makeScope` is now used, so it is possible to use `.overrideScope'` to set e.g. a different `cudnn` version;
- `release-cuda.nix` is introduced to easily evaluate cuda packages using hydra.
