update CUDA easyblock to add CUPTI and nvvm library directories to $LIBRARY_PATH

[trz42]

When using RPATH linking (e.g., in EESSI) we need to ensure that all directories containing shared libraries must be listed in $LIBRARY_PATH. Otherwise the RPATH linker wrapper would not add these directories to the RPATH header, and thus the libraries cannot be resolved by the dynamic linker later.

Here, we add two directories to LIBRARY_PATH such that corresponding prepend_path commands are added to the module file for CUDA. These directories are known to the easyblock, but currently only added to $LD_LIBRARY_PATH which is filtered in EESSI.

To restrict the change to certain environments, it is only used when LD_LIBRARY_PATH is a filtered environment variable and LIBRARY_PATH is not.

[ocaisa]

You don't want the stubs in the final RPATH, these need to come from the OS at runtime

[ocaisa]

Ah, sorry, this is explicitly filtered in framework (I am pretty sure...)

[ocaisa]

I think this can be much simpler than this, there's no need for the checking, you can just directly set

'LIBRARY_PATH': lib_path + [os.path.join('stubs', 'lib64')],

below. The stubs location is filtered out by the rpath wrappers at link time (which is correct).

[ocaisa]

The only difference between the link libraries and runtime libraries should be the stubs location

[trz42]

If we can always add extras/CUPTI/lib64 and nvvm/lib64 to LIBRARY_PATH, then we can implement it as you suggested.

BTW, while it may not be relevant anymore, CUPTI and nvvm lib dirs should only be added for CUDA 7 or newer. That's currently not the case in the PR, but would be following your suggestion.

[ocaisa]

The directories being added are just guesses, if they don't exist they won't be included in the final module file (I think...)

[trz42]

Implemented suggestions in 5077104