2023-08-07 Nix team meeting minutes #78

Only @edolstra and @regnat originally. @tom joining later on.



  • Should be experimental
  • Eelco left a bunch of comments, good to go once it’s resolved


Dmesg-based communication between stores

@tomberek raised an interesting possibility for two derivations to communicate by using the kernel logs (readable in the sandbox, and can be written to by segfaulting for instance). Not a huge deal (we don’t pretend that this kind of things is impossible), but good to know and avoid if we can.
@tomberek will open an issue about it.


  • Looks fairly good overall, and rather small PR for the feature
  • Would be nice to extend to support not purely local stores as the underlying one (to enable the CI case). But can be built on top of this later
  • Might be suboptimal for some use-cases because “simple” operations like “isValidPath” actually require traversing the whole closure on the underlying store (to bubble-it up to the upper layer).
  • Assigned to Eelco for further review