Re: [PATCH v3 1/3] fetch/git: add support for disabling shared clones on unpack

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

Note mainly to isar-users, this is now merged in upstream bitbake. Once
we update our bitbake we can set "BB_GIT_NOSHARED = 1" in our
bitbake.conf and drop the git adjust task. That should allow use of git
outside the chroot and hopefully does not have a too negative impact on
unpack performance ... for big things like the kernel

Henning

Am Wed, 14 Apr 2021 08:32:39 +0200
schrieb Henning Schild <henning.schild@siemens.com>:

> By default the unpacker will create a "shared" clone when cloning from
> the DL_DIR to the WORKDIR. This patch introduces an option to control
> that behaviour.
> 
> Imagine some recipe steps are executed in a namespace that is
> different from the one your downloader and unpacker ran in. (chroot)
> Because a "shared" clone has an absolute reference to its "alternate"
> you now have to make that "alternate" visible in that new namespace
> (chroot) at the exact place.
> 
> With this patch you can unpack "noshared" and get a stand-alone copy.
> This copy will also work if the "alternate" is not visible or
> existant.
> 
> The switch is a global bitbake switch and will affect all git urls.
> Build systems that need "noshared" most likely need it for everything
> they do with git.
> 
> Signed-off-by: Henning Schild <henning.schild@siemens.com>
> ---
>  lib/bb/fetch2/git.py | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/bb/fetch2/git.py b/lib/bb/fetch2/git.py
> index e3ba80a3f52a..3e25b4b6047c 100644
> --- a/lib/bb/fetch2/git.py
> +++ b/lib/bb/fetch2/git.py
> @@ -168,7 +168,11 @@ class Git(FetchMethod):
>          if len(branches) != len(ud.names):
>              raise bb.fetch2.ParameterError("The number of name and
> branch parameters is not balanced", ud.url) 
> -        ud.cloneflags = "-s -n"
> +        ud.noshared = d.getVar("BB_GIT_NOSHARED") == "1"
> +
> +        ud.cloneflags = "-n"
> +        if not ud.noshared:
> +            ud.cloneflags += " -s"
>          if ud.bareclone:
>              ud.cloneflags += " --mirror"
>