Re: [PATCH] dpkg-base: "unshare" git clones in adjust_git

[Henning Schild <henning.schild@siemens.com>]

Am Sun, 15 Aug 2021 20:55:34 +0200
schrieb Jan Kiszka <jan.kiszka@siemens.com>:

> On 13.08.21 19:49, Henning Schild wrote:
> > Instead of messing with the alternate make the clone not "shared"
> > anymore. Doing that will allow us to use git as a patchtool, also in
> > incremental rebuilds where do_patch might run again after
> > do_adjust_git
> > 
> > It will also make sure git repos will be usable in all three
> > environments. On a container host, inside the container, and inside
> > the chroot ... as apposed to only the chroot in the end.
> > 
> > Signed-off-by: Henning Schild <henning.schild@siemens.com>
> > ---
> >  meta/classes/dpkg-base.bbclass | 7 +++----
> >  1 file changed, 3 insertions(+), 4 deletions(-)
> > 
> > diff --git a/meta/classes/dpkg-base.bbclass
> > b/meta/classes/dpkg-base.bbclass index ec8fbc14d5e4..2a8e3ef4b817
> > 100644 --- a/meta/classes/dpkg-base.bbclass
> > +++ b/meta/classes/dpkg-base.bbclass
> > @@ -45,11 +45,11 @@ python do_adjust_git() {
> >              alternates = os.path.join(destdir,
> > ".git/objects/info/alternates") 
> >              if os.path.exists(alternates):
> > -                cmd = ["sed", "-i", alternates, "-e",
> > -
> > "s|{}|/downloads|".format(d.getVar("DL_DIR"))]
> > +                cmd = ["git", "-C", destdir, "repack", "-a" ]
> >                  bb.note(' '.join(cmd))
> >                  if subprocess.call(cmd) != 0:
> > -                    bb.fatal("git alternates adjustment failed")
> > +                    bb.fatal("git repack failed")
> > +                os.remove(alternates)
> >          except bb.fetch2.BBFetchException as e:
> >              bb.fatal(str(e))
> >  }
> > @@ -57,7 +57,6 @@ python do_adjust_git() {
> >  addtask adjust_git before do_dpkg_build
> >  
> >  inherit patch
> > -addtask patch before do_adjust_git
> >  
> >  SRC_APT ?= ""
> >  
> >   
> 
> NACK, we have a pattern now that avoids this.

Does that cover all three envs? (docker-host, docker, and chroots?)

If your ../../../.. thing works that might be fine, but this whole
approach with "sed" is git surgery not backed by documentation or
official interfaces.
The benefit of the deduplication is likely neglectible ... unless you
take the kernel as example. But even there you are probably saving much
more with going shallow than with deduplication via shared clones.

Henning

> Jan
>