$ git clone -n https://src.fedoraproject.org/rpms/rust-async-lock.git /var/lib/mock/f39-build-1499476-34745/root/chroot_tmpdir/scmroot/rust-async-lock
Cloning into '/var/lib/mock/f39-build-1499476-34745/root/chroot_tmpdir/scmroot/rust-async-lock'...
$ git fetch origin b7e6ddf4aba7a933f6470ec36c451bf63ec92e68:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-async-lock
 * [new ref]         b7e6ddf4aba7a933f6470ec36c451bf63ec92e68 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b7e6ddf Update to version 2.8.0; Fixes RHBZ#2230775