$ git clone -n https://src.fedoraproject.org/rpms/rust-stfu8.git /var/lib/mock/f39-build-2251784-54112/root/chroot_tmpdir/scmroot/rust-stfu8
Cloning into '/var/lib/mock/f39-build-2251784-54112/root/chroot_tmpdir/scmroot/rust-stfu8'...
$ git fetch origin 21541b64978513d663c92c3172e44f2870a9539f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-stfu8
 * [new ref]         21541b64978513d663c92c3172e44f2870a9539f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21541b6 Update to version 0.2.7; Fixes RHBZ#2257538