$ git clone -n https://src.fedoraproject.org/rpms/rust-cairo-rs0.20.git /var/lib/mock/f45-build-40615-773/root/chroot_tmpdir/scmroot/rust-cairo-rs0.20
Cloning into '/var/lib/mock/f45-build-40615-773/root/chroot_tmpdir/scmroot/rust-cairo-rs0.20'...
$ git fetch origin 21ed0d2f607a91717e026f0a26bd93f47269e3c3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cairo-rs0.20
 * [new ref]         21ed0d2f607a91717e026f0a26bd93f47269e3c3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 21ed0d2 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild