$ git clone -n https://src.fedoraproject.org/rpms/rust-option-ext.git /var/lib/mock/f45-build-43566-804/root/chroot_tmpdir/scmroot/rust-option-ext
Cloning into '/var/lib/mock/f45-build-43566-804/root/chroot_tmpdir/scmroot/rust-option-ext'...
$ git fetch origin c3cb1971f3bd781f12d1e2b5e03e8c3b8a0e61ec:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-option-ext
 * [new ref]         c3cb1971f3bd781f12d1e2b5e03e8c3b8a0e61ec -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c3cb197 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild