$ git clone -n https://src.fedoraproject.org/rpms/rust-mac.git /var/lib/mock/f45-build-43106-800/root/chroot_tmpdir/scmroot/rust-mac
Cloning into '/var/lib/mock/f45-build-43106-800/root/chroot_tmpdir/scmroot/rust-mac'...
$ git fetch origin 3607c9283a0464784a7c69cc602bf91b9d38c0f8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-mac
 * [new ref]         3607c9283a0464784a7c69cc602bf91b9d38c0f8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3607c92 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild