$ git clone -n https://src.fedoraproject.org/rpms/rust-salsa20_0.10.git /var/lib/mock/f45-build-44662-816/root/chroot_tmpdir/scmroot/rust-salsa20_0.10
Cloning into '/var/lib/mock/f45-build-44662-816/root/chroot_tmpdir/scmroot/rust-salsa20_0.10'...
$ git fetch origin f256f7a6b74210b4be44fee53e090d5bbf4a2e44:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-salsa20_0.10
 * [new ref]         f256f7a6b74210b4be44fee53e090d5bbf4a2e44 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f256f7a Initial compat package