$ git clone -n https://src.fedoraproject.org/rpms/rust-syn1.git /var/lib/mock/f45-build-45298-822/root/chroot_tmpdir/scmroot/rust-syn1
Cloning into '/var/lib/mock/f45-build-45298-822/root/chroot_tmpdir/scmroot/rust-syn1'...
$ git fetch origin 2dafffdde46ca60c22543e3da3bf5d78bd0eb894:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-syn1
 * [new ref]         2dafffdde46ca60c22543e3da3bf5d78bd0eb894 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2dafffd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild