Packages/pace

[hjjvandam]

The optional module ML-PACE in LAMMPS requires external code from https://github.com/ICAMS/lammps-user-pace.

This PR adds a Spack package to install Pace as a separate library, and modifies the LAMMPS package to build Pace as a dependency when ML-PACE is requested.

spack install lammps +ml-pace

installs LAMMPS with the ML-PACE module included.

[hjjvandam]

Apparently there are failures in the "ci/gitlab-ci". There are two kinds of failures:

1. aws-isc-build and e4s-power-build: "Unable to create pipeline", "Job e4s-power-generate not found in parent pipeline or does not have artifacts!". There is also a tag "yaml invalid".
2. e4s-cray-rhel-build: Error: ProcessError: Command exited with status 1:
   '/usr/bin/patch' '-s' '-p' '1' '-i' '/tmp/gitlab-runner-2/spack-stage/spack-stage-patch-b8d1f08a82329e493e040de2bde9d2291af173a0fe6c7deb24750cc22823c421/spack-src/49bdc3e26449634f150602a66d0dab34d09dbc0e.patch?full_index=1' '-d' '.'
   Ad 1. Is this a Spack problem? I have no idea what yaml file this error refers to and my changes are architecture independent. So I cannot see how this error is related to my changes. Anyone got any ideas?
   Ad 2. I don't know why patching the LAMMPS code failed. I didn't make any changes to LAMMPS. Also there is little information by the way of error messages as to what patch didn't like. What is the best way to proceed here?

[rbberger]

@hjjvandam for this to work the CMake install of pace would have to place the necessary files into its install prefix and the LAMMPS ML-PACE Cmake needs to be able to consume those files. Right now it assumes access to the LAMMPS/pace source code.

Right now you have to provide LOCAL_ML-PACE to a source location of PACE, otherwise it'll just try to download its known version fresh.

I've also started my own effort by providing ML-PACE as a LAMMPS plugin via Spack internally, which grabs both sources and builds a shared library that can be loaded at runtime.

But if it is possible to build PACE without LAMMPS sources, I'd prefer patching up the CMake in both projects.

Feel free to ping me in the LAMMPS/Spack slack.

[hjjvandam]

@rbberger I am happy to discuss this topic, but how do I get onto the LAMMPS/Spack slack? Is there a way you can invite me to the channel? I have just joined Slack with hubertus dot vandam at uni-due dot de. My organization normally doesn't use Slack (although my previous organization does).

[rbberger]

I'm "rberger" (one b) in both Spack and LAMMPS slack spaces. Just send me a direct message.