Hello everyone,
OpenMC 0.15.3 announced that MCPL is now a runtime dependency. But I am unable to get it working. Do I need some extra steps after the library is installed?
After the installation of both OpenMC + MCPL, the library is there:
mamba create -p /sw/openmc/latest-2026-03-25 python=3.12 mcpl openmc -c conda-forge --override-channels
ls -al /sw/openmc/latest-2026-03-25/lib/libmcpl.so
-rwxrwxr-x 2 root itcrowd 113200 Feb 18 16:58 /sw/openmc/latest-2026-03-25/lib/libmcpl.so
MCPL library seems to me to be in the right path:
$ whereis openmc
openmc: /sw/openmc/latest-2026-03-25/bin/openmc
$ /sw/openmc/latest-2026-03-25/bin/mcpl-config -s
MCPL v2.2.8 with configuration:
bindir : /sw/openmc/latest-2026-03-25/bin
build_type : Release
buildflags : -Wl,-rpath,/sw/openmc/latest-2026-03-25/lib -Wl,/sw/openmc/latest-2026-03-25/lib/libmcpl.so -I/sw/openmc/latest-2026-03-25/include
cmakedir : /sw/openmc/latest-2026-03-25/lib/cmake/MCPL
includedir : /sw/openmc/latest-2026-03-25/include
intversion : 2002008
libdir : /sw/openmc/latest-2026-03-25/lib
libname : libmcpl.so
libpath : /sw/openmc/latest-2026-03-25/lib/libmcpl.so
shlibdir : /sw/openmc/latest-2026-03-25/lib
shlibname : libmcpl.so
shlibpath : /sw/openmc/latest-2026-03-25/lib/libmcpl.so
version : 2.2.8
but the OpenMC does not load it
$ /sw/openmc/latest-2026-03-25/bin/openmc --version
OpenMC version 0.15.3
Commit hash: 27e38e894697bb32a1dac7848d2618818b6b8daf
Copyright (c) 2011-2025 MIT, UChicago Argonne LLC, and contributors
MIT/X license at https://docs.openmc.org/en/latest/license.html
Build type: Release
Compiler ID: GNU 14.3.0
MPI enabled: yes
Parallel HDF5 enabled: yes
PNG support: yes
DAGMC support: yes
libMesh support: no
MCPL support: no
Coverage testing: no
Profiling flags: no
UWUW support: no
Thank you for looking into this.
David