integrating pyAMReX bindings with app bindings?

[BenWibking]

Hi,

I have added a prototype Python binding for Quokka using pybind11:
https://github.com/quokka-astro/quokka/blob/BenWibking/python-bindings/src/bindings/pyquokka.cpp

However, I have been unable to get it to work with the pyAMReX bindings, for instance, having pyQuokka objects return pyAMReX multifab objects.

I tried to follow what pyWarpX does, but I am apparently missing something subtle. I have set up a Spack environment similar to the one recommended by WarpX. Then I configure a pyQuokka + pyAMReX + AMReX superbuild and get:

-- Build type: Debug
-- Performing Test HAS_NULLPTR_WARNING
-- Performing Test HAS_NULLPTR_WARNING - Success
-- Compiling local pyAMReX ...
-- pyAMReX source path: /Users/benwibking/amrex_codes/quokka/extern/pyamrex
-- AMReX::amrex target already imported
-- Found Python: /Users/benwibking/spack/opt/spack/darwin-m1/python-3.14.0-7yg77kt4w3hnkqejm5xlh3yvwp5kaejj/bin/python3 (found suitable version "3.14.0", minimum required is "3.8.0") found components: Interpreter Development.Module
-- Downloading pybind11 ...
-- pybind11 repository: https://github.com/pybind/pybind11.git (v3.0.1)
-- pybind11 v3.0.1
-- Performing Test HAS_FLTO_THIN
-- Performing Test HAS_FLTO_THIN - Success
-- Performing Test HAS_FLTO
-- Performing Test HAS_FLTO - Success
-- Found Git: /opt/homebrew/bin/git (found version "2.51.2")
-- pyAMReX: defaulting to 'pip install --user --break-system-packages'. Override via PY_PIP_INSTALL_OPTIONS to change.

pyAMReX build configuration:
  Version: 25.11
  C++ Compiler: AppleClang 17.0.0.17000319
    /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++

  Installation prefix: /usr/local
        bin: bin
        lib: lib
    include: include
      cmake: /pyAMReX
     python:

  Build type: Debug

At runtime, I get errors like this when using pyAMReX multifabs returned by pyQuokka:

Initializing AMReX (25.11-15-g4dad1664d746)...
MPI initialized with 1 MPI processes
MPI initialized with thread support level 0
AMReX (25.11-15-g4dad1664d746) initialized
Traceback (most recent call last):
  File "/Users/benwibking/amrex_codes/quokka/inputs/python/test_advection_prototype.py", line 58, in <module>
    raise SystemExit(main())
                     ~~~~^^
  File "/Users/benwibking/amrex_codes/quokka/inputs/python/test_advection_prototype.py", line 51, in main
    sim.run()
    ~~~~~~~^^
  File "/Users/benwibking/amrex_codes/quokka/inputs/python/test_advection_prototype.py", line 37, in diagnostics
    mf = sim.state()
RuntimeError: Could not activate keep_alive!

[BenWibking]

@ax3l If you can provide any advice on this issue, let me know.

[ax3l]

@BenWibking Thanks for the ping!

In your application, did you ensure pyamrex is imported first?

Example: https://github.com/BLAST-ImpactX/impactx/blob/0a1988461d57a561cc21b62dc380a06ba40d6937/src/python/pyImpactX.cpp#L34

[BenWibking]

That fixed it, thanks!