$ git clone -n https://src.fedoraproject.org/rpms/rust-siphasher0.3.git /var/lib/mock/f39-build-1848092-42172/root/chroot_tmpdir/scmroot/rust-siphasher0.3
Cloning into '/var/lib/mock/f39-build-1848092-42172/root/chroot_tmpdir/scmroot/rust-siphasher0.3'...
$ git fetch origin f8dee5ba20f834c54f230735a3a9ca26fe29c6d5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-siphasher0.3
 * [new ref]         f8dee5ba20f834c54f230735a3a9ca26fe29c6d5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f8dee5b Initial import (siphasher 0.3 compat package)