Conference notes for 2022 02 08

Agenda for 2022-02-08

• Q&A
• How to provide module properties to isVisible Hook
• Future Topics

Attendees

• Robert McLay (TACC, US)
• Kenneth Hoste (HPC-UGent, Belgium)
• Kurt Lust (Univ. of Antwerp (Belgium) + LUMI User Support Team)
• Ward Poelmans (HPC-VUB, Belgium)
• Åke Sandgren (Umeå Univ, Sweden)

How to provide module properties to isVisible Hook

• slides: https://github.com/TACC/Lmod/blob/master/my_docs/22/lmod_zoom_mtg_2022_02_08/presentation.pdf
• ModuleTable is uuencoded (base64) to not worry about quoting
  • also broken up into 256-char blocks (mostly because of limits in csh)
  • Lmod does the same things internally across all shells (to simplify things)
• read ModuleTable currently stored in environment via ml --mt (ml -mt would be unloading module named mt)
• ModuleTable is also stored in FrameStk to support break statements
• wV entry in ModuleTable is "weighted version"
  • inspired by LooseVersion in Python
• MTversion is version of ModuleTable format (important for saved module collections)
• while in load_hook
  • load_hook is triggered after loading of module is done in FrameStk
  • changes made to environment by module being loaded are also present in current environment
  • ModuleTable on top of stack reflects state after loading that module
  • ModuleTable stored in environment is not updated yet, that is only done after loading of module is complete (so after triggering of load_hook)

Q&A

• Question by Kurt on 'module avail' showing all extensions
  • see https://github.com/TACC/Lmod/issues/560
  • Robert's hasn't found time yet to look into this...

Future topics

• mname: going from user-provided name to a file that's associated with it
• walkthrough of Lmod internal workings: tracing how a module load command is processed?

Next meeting

• Next meeting (Tue 1 Mar 2022 - 15:30 UTC)
• Topic: Lmod Testing System
  • spoiler: https://github.com/TACC/Hermes
• likely significantly longer than previous calls (>1h)