test_expect_success 'setup repo' '
git init &&
git config core.commitGraph true &&
+ git config gc.writeCommitGraph false &&
infodir=".git/objects/info" &&
graphdir="$infodir/commit-graphs" &&
test_oid_init
git clone --no-hardlinks . alt-split &&
(
cd alt-split &&
+ rm -f .git/objects/info/commit-graph &&
echo "$(pwd)"/../.git/objects >.git/objects/info/alternates &&
test_commit 18 &&
git commit-graph write --reachable --split &&