Telcon: 2018 04 05

Attendees

• Todd Gamblin (LLNL)
• Dan Topa (LANL)
• Patrick Gartung (Fermi)
• Peter Scheibel (LLNL)
• Mario Melara (NERSC)

News

• Static/shared library variant updates

  • Peter Scheibel will be experimenting with a multi-valued variant convention for this.
  • possible values: (shared), (static), or (shared, static).
  • omitting static-pic for now, but this scheme leaves room for that if we want it later
  • also allows packages to declare which values they allow

• ECP, continuous integration, and release process updates

PRs of interest:

• Avoid double 'lib' for packages whose name already starts with lib: https://github.com/spack/spack/pull/7651
• make view understand hashes: https://github.com/spack/spack/pull/7573
• mirrors.yaml: does not expand: https://github.com/spack/spack/pull/7631
• Major improvements on NFS latency at startup:
  • Avoid stat-ing all packages at startup.: https://github.com/spack/spack/pull/7587

Issues

• Dan: can't get clang in core for lmod module config
• Patrick:
  • same compiler but different sets of cxx flags not working in lmod generation
  • two compilers, ~same version with version suffix not showing up differently
  • filed at https://github.com/spack/spack/issues/7679

Discussion

• Peter: Static/shared:
  • There should be a single-valued variant called "linktype" with the values "shared", "static", and "both"
    • Most packages would default to "shared"
    • This is better than a multi-valued variant because for example if a package supports only building shared XOR static then the allowed values could omit "both"
  • Packages should be individually edited to include a linktype variant (because some packages don't build any libs/executables and are just scripts)
  • Some packages may only build static, or only shared, and in that case a linktype variant still makes sense (mainly to keep track of dependency relationships) but e.g. it would only ever be one value
  • Generally, this variant is anticipated to dictate both the objects that are created, and how they are linked.
    • E.g. linktype=shared means "build shared objects and link them against shared libraries"
    • Which is to say that concretization should generally propagate shared/static to dependencies with the "link" deptype

Dan:

• don't use modules much at LANL but trying to bring them in
• really liking the Lmod configuration in Spack
• will try to push on the HPC team to use Lmod in production.