$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_yaml.git /var/lib/mock/f39-build-1535450-36247/root/chroot_tmpdir/scmroot/rust-serde_yaml
Cloning into '/var/lib/mock/f39-build-1535450-36247/root/chroot_tmpdir/scmroot/rust-serde_yaml'...
$ git fetch origin 738c2f352e651a139379f3656e6efbc236b467e1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_yaml
 * [new ref]         738c2f352e651a139379f3656e6efbc236b467e1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 738c2f3 Update to version 0.9.25; Fixes RHBZ#2223145