$ git clone -n https://src.fedoraproject.org/rpms/rust-roff.git /var/lib/mock/f45-build-44474-814/root/chroot_tmpdir/scmroot/rust-roff
Cloning into '/var/lib/mock/f45-build-44474-814/root/chroot_tmpdir/scmroot/rust-roff'...
$ git fetch origin bc2f2af500e4f01bedcc7bc48ca2ee946b523e02:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-roff
 * [new ref]         bc2f2af500e4f01bedcc7bc48ca2ee946b523e02 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bc2f2af Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild