@nicpa The Conda packages are intended to be highly portable but due to an error they were linking against a sysroot with GLIBC 2.39. I regenerated the mfix-solver package (now mfix-solver-26.1-h94061f0_1.conda, the _1 being the incremented build number) to force a 2.28 sysroot. This should work on Alma 9 and pretty much any other OS out there newer than CentOS 6.
However, since you’re installing on HPC, I sill recommend the HPC install, where you link against the MPI that is already installed, instead of getting a possibly incompatible version from conda-forge.
Please let me know if this works for you.
– Charles