make a vendor repo with shallow clone

vendor-repo-demo.sh

#!/usr/bin/env sh

cd $(mktemp -d)
echo "\n\n"
echo Step1: use temp dir: $(pwd)

echo "\n\n"
echo Step2: init main-repo
(
  mkdir main-repo
  git -C main-repo init --bare
) > /dev/null 2>&1

echo "\n\n"
echo Step3: prepare main-repo with 3 commits
(
  git clone main-repo workspace
  echo "secret" > workspace/secret.txt
  git -C workspace add -A
  git -C workspace commit -m "secret commit"
  git -C workspace revert HEAD --no-edit
  echo "public" > workspace/public.txt
  git -C workspace add -A
  git -C workspace commit -m "public commit"
  git -C workspace push
  rm -rf workspace
) > /dev/null 2>&1
echo show main-repo log
git -C main-repo log --oneline | cat

echo "\n\n"
echo Step4: make vendor-repo
(
  git clone --bare --depth 1 --branch master file://$(pwd)/main-repo vendor-repo
) > /dev/null 2>&1
echo show vendor-repo log
git -C vendor-repo log --oneline | cat

echo "\n\n"
echo Step5: make fork-repo
(
  git clone vendor-repo fork-repo
  echo "fork" > fork-repo/fork.txt
  git -C fork-repo add -A
  git -C fork-repo commit -m "fork commit"
) > /dev/null 2>&1
echo show fork-repo log
git -C fork-repo log --oneline | cat

echo "\n\n"
echo Step6: main-repo commit more
(
  git clone main-repo workspace
  echo "public more" >> workspace/public.txt
  git -C workspace add -A
  git -C workspace commit -m "one more public commit"
  git -C workspace push
  rm -rf workspace
) > /dev/null 2>&1
echo show main-repo log
git -C main-repo log --oneline | cat

echo "\n\n"
echo Step7: sync vendor-repo with main-repo
(
  git -C vendor-repo worktree add workspace master
  git -C vendor-repo/workspace pull file://$(pwd)/main-repo master
  git -C vendor-repo worktree remove workspace
) > /dev/null 2>&1
echo show vendor-repo log
git -C vendor-repo log --oneline | cat

echo "\n\n"
echo Step8: fork-repo merge commit from vendor-repo
(
  git -C fork-repo pull
) > /dev/null 2>&1
echo show fork-repo log
git -C fork-repo log --oneline | cat