bug#35181: Hydra offloads often get stuck while exporting build requisites

["Ludovic Courtès" <ludo@gnu.org>]

Mark H Weaver <mhw@netris.org> skribis:

> Also of note: So far, all known instances of this problem have occurred
> while transferring a large directory, as opposed to a tarball.
>
> We have several packages with source tarballs _much_ larger than these
> problematic source checkouts, and which are updated more much
> frequently, and yet I've *never* seen an instance of this problem while
> exporting a plain file to a build slave.  For example, the upstream
> IceCat and Firefox ESR tarballs are ~270 megabytes compressed, whereas
> 'font-google-material-design-icons-3.0.1' source is only ~176 megabytes
> _uncompressed_.
>
> I have no explanation for why the superficial form of the store item
> should matter here, but maybe it's a clue.  I know that plain
> non-executable files in the store are handled somewhat differently in
> the Nix model than directories or executable files, the latter
> associated with the word "recursive", and requiring an additional layer
> of encoding for purposes of serialization, but I'm not sufficiently
> familiar with the details or relevant code.
>
> Ludovic, can you think of a reason why the file/directory distinction
> could be relevant to this issue?

No, I can’t see why it could make a difference.

Ludo’.