NEST Hackathon 2022 Q4

This hackathon will result in the next time-based release: version 3.4.

Where: Jülich Research Centre, building 15.9 big top seminar room

When: 2022-11-28 to 2022-12-02

Participants

Get NEST 3.4 ready
- Go through list and sort milestone
review all PRs; reduce number of open PRs
clean up branches (feature branches accidently left over); clean up members of nest organization (Friday)
review what needs to happen for NESTML to replace all NEST built-in models
PyNEST-NG / Wheels (Jochen, Robin, Håkon)
New CI setup (Dennis)
Docker / Conda / for 3.4 (Steffen)
CMake for NESTGPU (Jose, Guido, Dennis)

Kernel architecture

Decision: typedefs without _t, as this is reserved by POSIX for system types.
Decision: unify internally used types to standard definitions, especially: size_t for everything used as an array index. Packing into bitfields for MPI transit or packed memory is an independent step and can raise exceptions when corresponding manager sees a problem (e.g. when using CopyModel(), Create(), SetKernelStatus(nvp=10000), …)
Development branch of NEST kernel without SLI dependency is now available, paving the way for cleaned Python and C++ APIs.

Install / Infrastructure

separated_checks branch has been advanced to be almost feature-complete wrt. monolithic ci_build.sh
Decision: cmake for C++ and library installs, pip responsible for Python installs. Don't let CMake guess a pythonpath… will break.
- prototyping the setup with NEST GPU has reached a clean pip install nestgpu pathway, which is expected to be adopted by NEST Simulator.
- fixes issue with PyNEST install to lib/…/site-packages vs. lib64/…/site-packages. Affected Spack package library paths (-DCMAKE_INSTALL_LIBDIR=lib), conda-forge packaging, Docker container (mv lib64/… lib/…) and HPC installs due to different system defaults and symlink conventions.
Fix: CMake handling of install flags (-Dwith-optimize=…) was improved in various additional cases.