Re: [bitbake-devel] [PATCH 1/1] bitbake: add BB_GIT_SHALLOW_SKIP_FAST to disable fast shallow mode

On Tue, 2026-05-05 at 01:08 -0700, Marcio Henriques via lists.openembedded.org wrote:
> We want to create a download mirror to store all sources needed to build a  
> specific project.
>  
> The idea is to use Git shallow tarballs because each tarball has a unique name.  
> This prevents files from being overwritten in the mirror. With full Git  
> tarballs, the name is always the same, so the mirror file gets replaced each  
> time. If something is removed from the upstream repository, we might upload a  
> new tarball that no longer contains a reference used by a recipe that was  
> already integrated.

FWIW the git fetcher is specifically coded to avoid removing
references. It shouldn't remove old revisions or obsolete heads (e.g.
for repos that changed master -> main). If it is doing that, that is
something we should fix.

> With shallow tarballs, we can safely clean DL_DIR since it's not the source of  
> truth. If something is removed from upstream, we fall back to the mirror and  
> use the shallow tarball.
>  
> For most of the builds, we want to use the bare clone in DL_DIR/git2 and just  
> update the repo when bumping a SRCREV. The DL_DIR/git2 repositories are  
> available on the machine that triggers the build.
>  
> The shallow tarball is a fallback for cases where something was removed from  
> the repository (for example, after a force push) and is not present in  
> DL_DIR/git2 or upstream, but was merged at some point. This is why we use Git  
> shallow and set shallow_skip_fast to True.

I can see why you might decide to do that but it will be a pretty
inefficient use of space with an archive for every revision and means
turning everything into shallow clones, which has its own challenges.

Cheers,

Richard