dev meeting 20230405

present: @alizter @arozovyk @emillon @kit-ty-kate @leonidas-from-xiv @lthls @nojb @rgrinberg

• @emillon to update link in invite
• 3.7.1 release
  • still running CI
  • already in nix
  • next steps: announce on discuss, merge changelog in main
• dune in nix
  • dune 2 being phased out
• 3.8 release
  • starting the work in 2 weeks
• opam/dune integration (@leonidas-from-xiv)
  • what source fetching is about: curl and unpack in a directory
  • opam is a large dependencies and has dependencies itself
  • after keeping just the minimum, it's still +21kloc
  • if we use the solver etc we won't be able to tree shake a ton
  • @nojb: raises concerns about size + how to vendor properly
  • discussions about what goes in the switch: dependencies, compiler? -> only per compiler version. no _opam directory
  • if we're just fetching, we have the same limitations as opam-monorepo
  • @nojb: second approach is building and "installing" dependencies.
  • @rgrinberg: we'd need new rules about when to rebuild packages
  • @rgrinberg to write a proposal. packages are built in a directory named after the hash of its deps (sandboxed) in a content adressable way
  • @alizter: for projects depend on dune. do dependencies fetch dune? -> in monorepo it's special cased
  • what about multi-context builds (x-compilation or multi-version)? @rgrinberg: for v1, no difference between dune and non dune packages
  • integration strategy
    • @rgrinberg raises concerns about rebase costs
    • @emillon raises concerts about binary size and revertability
    • we agree that it's good to explore this
  • end status:
    • dune and opam are going to coexist
    • opam-repository to continue existing
    • we can upstream changes to opam
    • opam team on board
  • question about dune build - does it fetch sources by itself?
    • we want to avoid commands that ask to run a command
    • source fetching is just a rule with no dependencies
• dependency work (@arozovyk @lthls)
  • questions about comparing names between dune libraries and main module of library
  • would need to build a map
  • cannot really do that for dependencies that do not use dune but this probably not an issue for these