# Brian2cuda compilation issues **URL:** \ **Category:** Support\ **Tags:** brian2cuda\ **Created:** [15 March 2024 03:44 UTC](https://brian.discourse.group/t/brian2cuda-compilation-issues/1165 "2024-03-15T03:44:03Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![kjohnsen](https://yyz2.discourse-cdn.com/free1/user_avatar/brian.discourse.group/kjohnsen/32/200_2.png) [@kjohnsen](https://brian.discourse.group/u/kjohnsen)\ **Post date:** [15 March 2024 03:44 UTC](https://brian.discourse.group/t/brian2cuda-compilation-issues/1165/1 "2024-03-15T03:44:03Z")
# Description of problem brian2cuda compilation is failing and I don’t know why. I don’t expect anyone to be able to fully debug since this is specific to my system, but maybe someone has seen things like this before and could point me in a useful direction. I get compiler errors (parameter packs not expanded with ‘…’) as well as a regex warning about an invalid escape sequence. # Relevant details - I’m on WSL Ubuntu-22 - I installed `sudo apt install nvidia-cuda-toolkit`, which seemed to work. nvcc is in the path, and brian2cuda picks up on it, as well as my GPU (see output below). - I have the right pair of brian2cuda (v1.0a3) and brian2 (v2.5.4) - nvcc version 11.5, if that’s relevant - g++ (version provided by apt) is up to date - I’m running `brian2cuda.example_run()` - I also tried cuda-samples@v11.5 and some of those programs also cause the same ‘parameter packs’ error, so this is almost for sure a problem with my underlying CUDA setup # Full traceback of error (if relevant) ```auto INFO CUDA installation directory detected via location of `nvcc` binary: /usr [brian2.devices.cuda_standalone] INFO Compiling device code for GPU 0 (NVIDIA GeForce GTX 1650) [brian2.devices.cuda_standalone] INFO Compiling device code for compute capability 7.5 (compiler flags: ['-arch=sm_75']) [brian2.devices.cuda_standalone] INFO Using the following preferences for CUDA standalone: [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.SM_multiplier = 1 [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.parallel_blocks = 1 [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.launch_bounds = False [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.syn_launch_bounds = False [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.calc_occupancy = True [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.extra_threshold_kernel = True [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.random_number_generator_type = CURAND_RNG_PSEUDO_DEFAULT [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.random_number_generator_ordering = False [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.push_synapse_bundles = True [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.threads_per_synapse_bundle = {max} [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.bundle_threads_warp_multiple = False [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.no_pre_references = False [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.no_post_references = False [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.default_functions_integral_convertion = [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.use_atomics = True [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.profile_statemonitor_copy_to_host = None [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.gpu_heap_size = 128 [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.detect_gpus = True [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.gpu_id = None [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.extra_compile_args_nvcc = ['-w', '-use_fast_math'] [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.compute_capability = None [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.detect_cuda = True [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.cuda_path = None [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.cuda_runtime_version = None [brian2.devices.cuda_standalone] INFO devices.cuda_standalone.cuda_backend.device_query_path = None [brian2.devices.cuda_standalone] /usr/include/c++/11/bits/std_function.h:435:145: error: parameter packs not expanded with ‘...’: 435 | function(_Functor&& __f) | ^ /usr/include/c++/11/bits/std_function.h:435:145: note: ‘_ArgTypes’ /usr/include/c++/11/bits/std_function.h:530:146: error: parameter packs not expanded with ‘...’: 530 | operator=(_Functor&& __f) | ^ [...the same errors repeated many times...] WARNING /home/kyle/miniforge3/envs/cleo/lib/python3.12/site-packages/brian2cuda/device.py:1967: SyntaxWarning: invalid escape sequence '\w' match = re.search('_binomial\w*\(const int vectorisation_idx\)', codeobj.code.cu_file) ``` ---
**Author:** ![mstimberg](https://yyz2.discourse-cdn.com/free1/user_avatar/brian.discourse.group/mstimberg/32/11_2.png) [@mstimberg](https://brian.discourse.group/u/mstimberg)\ **Post date:** [15 March 2024 08:50 UTC](https://brian.discourse.group/t/brian2cuda-compilation-issues/1165/2 "2024-03-15T08:50:47Z")
Apparently it is a rather common issue, and has to do with an incompatibility between CUDA 11 and gcc 11 (or at least for some minor versions of them). From [this stackoverflow answer](https://github.com/NVlabs/instant-ngp/issues/119#issuecomment-1698809070), the most straightforward solution seems to use gcc 10 instead: ```auto sudo apt install gcc-10 g++-10 sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-10 10 sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-10 10 sudo update-alternatives --config gcc sudo update-alternatives --config g++ ``` Maybe widespread enough to put into known issues? ---
**Author:** ![kjohnsen](https://yyz2.discourse-cdn.com/free1/user_avatar/brian.discourse.group/kjohnsen/32/200_2.png) [@kjohnsen](https://brian.discourse.group/u/kjohnsen)\ **Post date:** [15 March 2024 20:54 UTC](https://brian.discourse.group/t/brian2cuda-compilation-issues/1165/3 "2024-03-15T20:54:24Z")
Thanks! I got it working. I still had the same problems with g++ 10, 9, and 12, so I actually had to change my CUDA toolkit version. I ran `mamba install cuda -c nvidia/label/cuda-11.6.0` to get nvcc 11.6 instead of 11.5, after which g++ 10 or 9 worked (but still not 11 or 12)