Hi Ludo, On Mon, 29 Jun 2020 at 14:34, Ludovic Courtès <l...@gnu.org> wrote:
> I realize I was a bit off-topic: I was commenting on the more general > issue of .go non-reproducibility. > > The problem with the package cache seems to be different. Sorry for the > confusion! Well, the .go non-reproducibility is nonetheless interesting. :-) > So, surprisingly, it’s not just an ordering issue: the caches do contain > different pieces of information. Interestingly, on my machine with 8ea91d0, I have 12 differences but none of them is Python. Instead, I have: "rust", "ocaml", "mingw-w64-i686", "clang-toolchain", "clang-runtime", "linux-libre", "icedtea", "gcc-objc++", "gcc-objc", "bdb", "rust-lazy-static", "gcc-toolchain". All are aliases and python-2 is too but does not appear... On the other hand, these 2 aliases do not appear either in your list. --8<---------------cut here---------------start------------->8--- (define-public clang clang-9) (define-public clang-toolchain clang-toolchain-9) --8<---------------cut here---------------end--------------->8--- The question is: do we need to declare public e.g. clang-9? Declare clang is it not enough already? For example, ocaml-4.09 is not used outside gnu/packages/ocalm.scm. Idem for ghc-8.6, etc.. > This patch solves the ordering issue The 'sort' will not help for improving the speed of "guix pull". ;-) > But it’s not quite right because the order in which variables are > traversed is still non-deterministic, so between two runs of > ‘generate-package-cache’, caches differ like this: It depends on the eddy current in the upper atmosphere. :-) https://xkcd.com/378/ Well, it finds one or the other first and 'expand-cache' stores the first considering the second as "seen", isn't it? > The problem has to do with aliases: we don’t always see the same > variable first. So we have to sort before calling ‘expand-cache’. The question is why it is not always the same variable first. Well, IMHO, it could comes from: - either 'scandir*' in 'scheme-files' because all the other functions seem "pure" and this one not; - either 'fold-module-public-variables*' where 'seen' is one or the other. Or if the .go files are not deterministic, especially about 'gensym', it should explain why one symbol appears sometimes first. Cheers, simon
