Rebuildling software years later

[Julien Malka]

Hello everyone,

(One of the) author of the article here,

>Nice!  I and others in the Guix community have been looking at
>rebuilding packages from source 5 years later using ‘guix time-machine’
>(my understanding is that the paper above is about re-downloading
>pre-built binaries, as per Section 3.2):
>
>  https://guix.gnu.org/en/blog/2024/adventures-on-the-quest-for-long-term-reproducible-deployment/
>
>This proves to be tricky, in particular due to “time traps”—builds or
>tests that start failing after a certain date.

Just wanted to add a little precision about this remark:
We state in the paper that we rely extensively on the NixOS cache. We
have indeed used the cache to fetch the dependencies of a given software 
but we have performed the build step locally, we have not merely checked 
that the pre-build results exist in the cache. It would be indeed harder 
not to rely on the cache *at all*, but to test the build phase of a package
in isolation we have decided to make the assumption that all its dependencies
are available to us.

I am of course very happy to discuss this research and are ongoing
projects with anyone interested.

Best,
Julien