$ git clone -n https://src.fedoraproject.org/rpms/aws-c-cal.git /var/lib/mock/f38-build-side-42-init-devel-846135-28422/root/chroot_tmpdir/scmroot/aws-c-cal
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-846135-28422/root/chroot_tmpdir/scmroot/aws-c-cal'...
$ git fetch origin aa66aaa209d269d8aaf006ff5a87af47f84c401a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/aws-c-cal
 * [new ref]         aa66aaa209d269d8aaf006ff5a87af47f84c401a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aa66aaa Added the README