Non-deterministic package IDs are really bad in 7.10

Joachim Breitner mail at
Thu May 14 18:36:30 UTC 2015


Am Sonntag, den 10.05.2015, 19:39 +0100 schrieb Mateusz Kowalczyk:
> I'd like to bring some attention to ticket #4012 about non-determinism.
> As many of you may know, the nix package manager distributes binaries
> throughout its binary caches. The binaries are shared as long as the
> hash of some of their inputs matches: this means that we can end up with
> two of the same hashes of inputs but thanks to #4012 means that the
> actual contents can differ. You end up with machines with some packages
> built locally and some elsewhere and due to non-determinism, the GHC
> package IDs don't line up and everything is broken.

is NixOS sensitive to changes in the build directory. Debian is, and
since 7.8 the build path creeps into the interface files and affects the

But you probably are not, otherwise you’d have complained when 7.8 was
out, and not now :-)


Joachim “nomeata” Breitner
  mail at joachim-breitner.de
  Jabber: nomeata at  • GPG-Key: 0xF0FBF51F
  Debian Developer: nomeata at
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