[PATCH v2] buildman: Use git worktrees instead of git clones when possible

[Simon Glass]

On Thu, 3 Sep 2020 at 06:51, Alper Nebi Yasak <alpernebiyasak at gmail.com> wrote:
>
> This patch makes buildman create linked working trees instead of clones
> of the source repository, but keeps updating the older clones of the
> repository that might already exist. These worktrees share "everything
> except working directory specific files such as HEAD, index, etc." with
> the source repository. See the git-worktree(1) manual page for more
> information.
>
> If git-worktree isn't available, silently falls back to cloning the
> repository.
>
> Signed-off-by: Alper Nebi Yasak <alpernebiyasak at gmail.com>
> ---
> I used 'git worktree list's return code, since 'git worktree' returns
> non-zero (prints usage) even if it's available.
>
> This does fall back to git clone on my Ubuntu 14.04 amd64 VM, but all
> the builds instantly give an error about the Makefile even before this
> patch. The buildman parts are working as far as I can tell.
>
> Changes in v2:
> - Fall back to cloning if git-worktree isn't available
> - Add a gitutil.CheckWorktreeIsAvailable(git_dir) function
> - Refactor the _PrepareThread changes
> - Make _PrepeareThread's setup_git argument accept 'clone' or 'worktree'
> - Some comment and docstring changes
>
> v1: https://patchwork.ozlabs.org/project/uboot/list/?series=199060
>
>  tools/buildman/builder.py   | 48 ++++++++++++++++++++++++++++++-------
>  tools/buildman/func_test.py |  2 ++
>  tools/patman/gitutil.py     | 42 ++++++++++++++++++++++++++++++++
>  3 files changed, 84 insertions(+), 8 deletions(-)

Reviewed-by: Simon Glass <sjg at chromium.org>