$ git clone -n https://src.fedoraproject.org/rpms/rust-pollster.git /var/lib/mock/f45-build-43998-809/root/chroot_tmpdir/scmroot/rust-pollster
Cloning into '/var/lib/mock/f45-build-43998-809/root/chroot_tmpdir/scmroot/rust-pollster'...
$ git fetch origin 0b65fbf9102fafad94e3c3ebf1914862d3654a2e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pollster
 * [new ref]         0b65fbf9102fafad94e3c3ebf1914862d3654a2e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0b65fbf Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild