Hi Vagrant,

On Thu, 13 Aug 2020 09:47:21 -0700
Vagrant Cascadian <vagrant@reproducible-builds.org> wrote:

> The source checkout was quite slow to download, and took up ~1GB in the
> store once completed. I'm not sure how guix's git origin works exactly;

git init
git remote add origin <url>
if git fetch --depth 1 origin <commit>
then
  git checkout FETCH_HEAD
else
  echo "Failed to do a shallow fetch; retrying a full fetch..."
  git fetch origin
  git checkout <commit>
fi
if ,recursive?
then
  git submodule update --init --recursive
  rm -rf .git for each submodule
fi
rm -rf .git

See guix/build/git.scm .

There exist git servers that have disabled fetching by commit hash for
"security" reasons (if you checked in a file containing a password and
then removed it again, and no branch or tag to it exists, nobody can
get to it even if he knew the commit hash).  We would always use the
fallback for those servers.

> if it downloads the entire git history even to perform a shallow
> checkout of a single commit, and then throws out the git history?

As a fallback if the above doesn't work.

> appear to be calling git with flags to perform a shallow checkout.

Yes.