Re: Parallel guix builds can trample?

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

Maxime Devos <maximedevos@telenet.be> skribis:

> Phil Beadling schreef op ma 17-01-2022 om 17:23 [+0000]:
>> For each build that is kicked off in quick succession the local cache
>> of the repo required updated by update-cached-checkout
>>  * https://github.com/guix-
>> mirror/guix/blob/9f526f5dad5f4af69d158c50369e182305147f3b/guix/git.sc
>> m#L476
>>  * https://github.com/guix-
>> mirror/guix/blob/9f526f5dad5f4af69d158c50369e182305147f3b/guix/git.sc
>> m#L279
>
>
> Maybe 'latest-repository-commit' and 'update-cached-checkout' commit
> can be modified to not use 'switch-to-ref', and instead directly ask
> libgit ‘what's the tree structure of commit cabba9e’ and call a
> procedure like 'add-file-tree-to-store'.  That would avoid lock files,
> creating separate directories for concurrent checkouts, ...

That would be ideal.  In Guix ‘write-file-tree’ already supports some
sort of virtual file systems, so it should be possible to use it to feed
the contents of the Git tree to the store.

Ludo’.